research report unique features/characteristics

• Research Report: Definition, Types + [Writing Guide]

One of the reasons for carrying out research is to add to the existing body of knowledge. Therefore, when conducting research, you need to document your processes and findings in a research report. 

With a research report, it is easy to outline the findings of your systematic investigation and any gaps needing further inquiry. Knowing how to create a detailed research report will prove useful when you need to conduct research.  

What is a Research Report?

A research report is a well-crafted document that outlines the processes, data, and findings of a systematic investigation. It is an important document that serves as a first-hand account of the research process, and it is typically considered an objective and accurate source of information.

In many ways, a research report can be considered as a summary of the research process that clearly highlights findings, recommendations, and other important details. Reading a well-written research report should provide you with all the information you need about the core areas of the research process.

Features of a Research Report 

So how do you recognize a research report when you see one? Here are some of the basic features that define a research report. 

• It is a detailed presentation of research processes and findings, and it usually includes tables and graphs. 
• It is written in a formal language.
• A research report is usually written in the third person.
• It is informative and based on first-hand verifiable information.
• It is formally structured with headings, sections, and bullet points.
• It always includes recommendations for future actions. 

Types of Research Report 

The research report is classified based on two things; nature of research and target audience.

Nature of Research

• Qualitative Research Report

This is the type of report written for qualitative research . It outlines the methods, processes, and findings of a qualitative method of systematic investigation. In educational research, a qualitative research report provides an opportunity for one to apply his or her knowledge and develop skills in planning and executing qualitative research projects.

A qualitative research report is usually descriptive in nature. Hence, in addition to presenting details of the research process, you must also create a descriptive narrative of the information.

• Quantitative Research Report

A quantitative research report is a type of research report that is written for quantitative research. Quantitative research is a type of systematic investigation that pays attention to numerical or statistical values in a bid to find answers to research questions. 

In this type of research report, the researcher presents quantitative data to support the research process and findings. Unlike a qualitative research report that is mainly descriptive, a quantitative research report works with numbers; that is, it is numerical in nature. 

Target Audience

Also, a research report can be said to be technical or popular based on the target audience. If you’re dealing with a general audience, you would need to present a popular research report, and if you’re dealing with a specialized audience, you would submit a technical report. 

• Technical Research Report

A technical research report is a detailed document that you present after carrying out industry-based research. This report is highly specialized because it provides information for a technical audience; that is, individuals with above-average knowledge in the field of study. 

In a technical research report, the researcher is expected to provide specific information about the research process, including statistical analyses and sampling methods. Also, the use of language is highly specialized and filled with jargon. 

Examples of technical research reports include legal and medical research reports. 

• Popular Research Report

A popular research report is one for a general audience; that is, for individuals who do not necessarily have any knowledge in the field of study. A popular research report aims to make information accessible to everyone. 

It is written in very simple language, which makes it easy to understand the findings and recommendations. Examples of popular research reports are the information contained in newspapers and magazines. 

Importance of a Research Report 

• Knowledge Transfer: As already stated above, one of the reasons for carrying out research is to contribute to the existing body of knowledge, and this is made possible with a research report. A research report serves as a means to effectively communicate the findings of a systematic investigation to all and sundry.  
• Identification of Knowledge Gaps: With a research report, you’d be able to identify knowledge gaps for further inquiry. A research report shows what has been done while hinting at other areas needing systematic investigation. 
• In market research, a research report would help you understand the market needs and peculiarities at a glance. 
• A research report allows you to present information in a precise and concise manner. 
• It is time-efficient and practical because, in a research report, you do not have to spend time detailing the findings of your research work in person. You can easily send out the report via email and have stakeholders look at it. 

Guide to Writing a Research Report

A lot of detail goes into writing a research report, and getting familiar with the different requirements would help you create the ideal research report. A research report is usually broken down into multiple sections, which allows for a concise presentation of information.

Structure and Example of a Research Report

This is the title of your systematic investigation. Your title should be concise and point to the aims, objectives, and findings of a research report. 

• Table of Contents

This is like a compass that makes it easier for readers to navigate the research report.

An abstract is an overview that highlights all important aspects of the research including the research method, data collection process, and research findings. Think of an abstract as a summary of your research report that presents pertinent information in a concise manner. 

An abstract is always brief; typically 100-150 words and goes straight to the point. The focus of your research abstract should be the 5Ws and 1H format – What, Where, Why, When, Who and How. 

• Introduction

Here, the researcher highlights the aims and objectives of the systematic investigation as well as the problem which the systematic investigation sets out to solve. When writing the report introduction, it is also essential to indicate whether the purposes of the research were achieved or would require more work.

In the introduction section, the researcher specifies the research problem and also outlines the significance of the systematic investigation. Also, the researcher is expected to outline any jargons and terminologies that are contained in the research.  

• Literature Review

A literature review is a written survey of existing knowledge in the field of study. In other words, it is the section where you provide an overview and analysis of different research works that are relevant to your systematic investigation. 

It highlights existing research knowledge and areas needing further investigation, which your research has sought to fill. At this stage, you can also hint at your research hypothesis and its possible implications for the existing body of knowledge in your field of study. 

• An Account of Investigation

This is a detailed account of the research process, including the methodology, sample, and research subjects. Here, you are expected to provide in-depth information on the research process including the data collection and analysis procedures. 

In a quantitative research report, you’d need to provide information surveys, questionnaires and other quantitative data collection methods used in your research. In a qualitative research report, you are expected to describe the qualitative data collection methods used in your research including interviews and focus groups. 

In this section, you are expected to present the results of the systematic investigation. 

This section further explains the findings of the research, earlier outlined. Here, you are expected to present a justification for each outcome and show whether the results are in line with your hypotheses or if other research studies have come up with similar results.

• Conclusions

This is a summary of all the information in the report. It also outlines the significance of the entire study. 

• References and Appendices

This section contains a list of all the primary and secondary research sources. 

Tips for Writing a Research Report

• Define the Context for the Report

As is obtainable when writing an essay, defining the context for your research report would help you create a detailed yet concise document. This is why you need to create an outline before writing so that you do not miss out on anything. 

• Define your Audience

Writing with your audience in mind is essential as it determines the tone of the report. If you’re writing for a general audience, you would want to present the information in a simple and relatable manner. For a specialized audience, you would need to make use of technical and field-specific terms. 

• Include Significant Findings

The idea of a research report is to present some sort of abridged version of your systematic investigation. In your report, you should exclude irrelevant information while highlighting only important data and findings. 

• Include Illustrations

Your research report should include illustrations and other visual representations of your data. Graphs, pie charts, and relevant images lend additional credibility to your systematic investigation.

• Choose the Right Title

A good research report title is brief, precise, and contains keywords from your research. It should provide a clear idea of your systematic investigation so that readers can grasp the entire focus of your research from the title. 

• Proofread the Report

Before publishing the document, ensure that you give it a second look to authenticate the information. If you can, get someone else to go through the report, too, and you can also run it through proofreading and editing software. 

How to Gather Research Data for Your Report  

• Understand the Problem

Every research aims at solving a specific problem or set of problems, and this should be at the back of your mind when writing your research report. Understanding the problem would help you to filter the information you have and include only important data in your report. 

• Know what your report seeks to achieve

This is somewhat similar to the point above because, in some way, the aim of your research report is intertwined with the objectives of your systematic investigation. Identifying the primary purpose of writing a research report would help you to identify and present the required information accordingly. 

• Identify your audience

Knowing your target audience plays a crucial role in data collection for a research report. If your research report is specifically for an organization, you would want to present industry-specific information or show how the research findings are relevant to the work that the company does. 

• Create Surveys/Questionnaires

A survey is a research method that is used to gather data from a specific group of people through a set of questions. It can be either quantitative or qualitative. 

A survey is usually made up of structured questions, and it can be administered online or offline. However, an online survey is a more effective method of research data collection because it helps you save time and gather data with ease. 

You can seamlessly create an online questionnaire for your research on Formplus . With the multiple sharing options available in the builder, you would be able to administer your survey to respondents in little or no time. 

Formplus also has a report summary too l that you can use to create custom visual reports for your research.

Step-by-step guide on how to create an online questionnaire using Formplus  

• Sign into Formplus

In the Formplus builder, you can easily create different online questionnaires for your research by dragging and dropping preferred fields into your form. To access the Formplus builder, you will need to create an account on Formplus. 

Once you do this, sign in to your account and click on Create new form to begin. 

• Edit Form Title : Click on the field provided to input your form title, for example, “Research Questionnaire.”
• Edit Form : Click on the edit icon to edit the form.
• Add Fields : Drag and drop preferred form fields into your form in the Formplus builder inputs column. There are several field input options for questionnaires in the Formplus builder. 
• Edit fields
• Click on “Save”
• Form Customization: With the form customization options in the form builder, you can easily change the outlook of your form and make it more unique and personalized. Formplus allows you to change your form theme, add background images, and even change the font according to your needs. 
• Multiple Sharing Options: Formplus offers various form-sharing options, which enables you to share your questionnaire with respondents easily. You can use the direct social media sharing buttons to share your form link to your organization’s social media pages.  You can also send out your survey form as email invitations to your research subjects too. If you wish, you can share your form’s QR code or embed it on your organization’s website for easy access. 

Conclusion  

Always remember that a research report is just as important as the actual systematic investigation because it plays a vital role in communicating research findings to everyone else. This is why you must take care to create a concise document summarizing the process of conducting any research. 

In this article, we’ve outlined essential tips to help you create a research report. When writing your report, you should always have the audience at the back of your mind, as this would set the tone for the document. 

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Home » Research Report – Example, Writing Guide and Types

Research Report – Example, Writing Guide and Types

Table of Contents

Research Report

Definition:

Research Report is a written document that presents the results of a research project or study, including the research question, methodology, results, and conclusions, in a clear and objective manner.

The purpose of a research report is to communicate the findings of the research to the intended audience, which could be other researchers, stakeholders, or the general public.

Components of Research Report

Components of Research Report are as follows:

Introduction

The introduction sets the stage for the research report and provides a brief overview of the research question or problem being investigated. It should include a clear statement of the purpose of the study and its significance or relevance to the field of research. It may also provide background information or a literature review to help contextualize the research.

Literature Review

The literature review provides a critical analysis and synthesis of the existing research and scholarship relevant to the research question or problem. It should identify the gaps, inconsistencies, and contradictions in the literature and show how the current study addresses these issues. The literature review also establishes the theoretical framework or conceptual model that guides the research.

Methodology

The methodology section describes the research design, methods, and procedures used to collect and analyze data. It should include information on the sample or participants, data collection instruments, data collection procedures, and data analysis techniques. The methodology should be clear and detailed enough to allow other researchers to replicate the study.

The results section presents the findings of the study in a clear and objective manner. It should provide a detailed description of the data and statistics used to answer the research question or test the hypothesis. Tables, graphs, and figures may be included to help visualize the data and illustrate the key findings.

The discussion section interprets the results of the study and explains their significance or relevance to the research question or problem. It should also compare the current findings with those of previous studies and identify the implications for future research or practice. The discussion should be based on the results presented in the previous section and should avoid speculation or unfounded conclusions.

The conclusion summarizes the key findings of the study and restates the main argument or thesis presented in the introduction. It should also provide a brief overview of the contributions of the study to the field of research and the implications for practice or policy.

The references section lists all the sources cited in the research report, following a specific citation style, such as APA or MLA.

The appendices section includes any additional material, such as data tables, figures, or instruments used in the study, that could not be included in the main text due to space limitations.

Types of Research Report

Types of Research Report are as follows:

Thesis is a type of research report. A thesis is a long-form research document that presents the findings and conclusions of an original research study conducted by a student as part of a graduate or postgraduate program. It is typically written by a student pursuing a higher degree, such as a Master’s or Doctoral degree, although it can also be written by researchers or scholars in other fields.

Research Paper

Research paper is a type of research report. A research paper is a document that presents the results of a research study or investigation. Research papers can be written in a variety of fields, including science, social science, humanities, and business. They typically follow a standard format that includes an introduction, literature review, methodology, results, discussion, and conclusion sections.

Technical Report

A technical report is a detailed report that provides information about a specific technical or scientific problem or project. Technical reports are often used in engineering, science, and other technical fields to document research and development work.

Progress Report

A progress report provides an update on the progress of a research project or program over a specific period of time. Progress reports are typically used to communicate the status of a project to stakeholders, funders, or project managers.

Feasibility Report

A feasibility report assesses the feasibility of a proposed project or plan, providing an analysis of the potential risks, benefits, and costs associated with the project. Feasibility reports are often used in business, engineering, and other fields to determine the viability of a project before it is undertaken.

Field Report

A field report documents observations and findings from fieldwork, which is research conducted in the natural environment or setting. Field reports are often used in anthropology, ecology, and other social and natural sciences.

Experimental Report

An experimental report documents the results of a scientific experiment, including the hypothesis, methods, results, and conclusions. Experimental reports are often used in biology, chemistry, and other sciences to communicate the results of laboratory experiments.

Case Study Report

A case study report provides an in-depth analysis of a specific case or situation, often used in psychology, social work, and other fields to document and understand complex cases or phenomena.

Literature Review Report

A literature review report synthesizes and summarizes existing research on a specific topic, providing an overview of the current state of knowledge on the subject. Literature review reports are often used in social sciences, education, and other fields to identify gaps in the literature and guide future research.

Research Report Example

Following is a Research Report Example sample for Students:

Title: The Impact of Social Media on Academic Performance among High School Students

This study aims to investigate the relationship between social media use and academic performance among high school students. The study utilized a quantitative research design, which involved a survey questionnaire administered to a sample of 200 high school students. The findings indicate that there is a negative correlation between social media use and academic performance, suggesting that excessive social media use can lead to poor academic performance among high school students. The results of this study have important implications for educators, parents, and policymakers, as they highlight the need for strategies that can help students balance their social media use and academic responsibilities.

Introduction:

Social media has become an integral part of the lives of high school students. With the widespread use of social media platforms such as Facebook, Twitter, Instagram, and Snapchat, students can connect with friends, share photos and videos, and engage in discussions on a range of topics. While social media offers many benefits, concerns have been raised about its impact on academic performance. Many studies have found a negative correlation between social media use and academic performance among high school students (Kirschner & Karpinski, 2010; Paul, Baker, & Cochran, 2012).

Given the growing importance of social media in the lives of high school students, it is important to investigate its impact on academic performance. This study aims to address this gap by examining the relationship between social media use and academic performance among high school students.

Methodology:

The study utilized a quantitative research design, which involved a survey questionnaire administered to a sample of 200 high school students. The questionnaire was developed based on previous studies and was designed to measure the frequency and duration of social media use, as well as academic performance.

The participants were selected using a convenience sampling technique, and the survey questionnaire was distributed in the classroom during regular school hours. The data collected were analyzed using descriptive statistics and correlation analysis.

The findings indicate that the majority of high school students use social media platforms on a daily basis, with Facebook being the most popular platform. The results also show a negative correlation between social media use and academic performance, suggesting that excessive social media use can lead to poor academic performance among high school students.

Discussion:

The results of this study have important implications for educators, parents, and policymakers. The negative correlation between social media use and academic performance suggests that strategies should be put in place to help students balance their social media use and academic responsibilities. For example, educators could incorporate social media into their teaching strategies to engage students and enhance learning. Parents could limit their children’s social media use and encourage them to prioritize their academic responsibilities. Policymakers could develop guidelines and policies to regulate social media use among high school students.

Conclusion:

In conclusion, this study provides evidence of the negative impact of social media on academic performance among high school students. The findings highlight the need for strategies that can help students balance their social media use and academic responsibilities. Further research is needed to explore the specific mechanisms by which social media use affects academic performance and to develop effective strategies for addressing this issue.

Limitations:

One limitation of this study is the use of convenience sampling, which limits the generalizability of the findings to other populations. Future studies should use random sampling techniques to increase the representativeness of the sample. Another limitation is the use of self-reported measures, which may be subject to social desirability bias. Future studies could use objective measures of social media use and academic performance, such as tracking software and school records.

Implications:

The findings of this study have important implications for educators, parents, and policymakers. Educators could incorporate social media into their teaching strategies to engage students and enhance learning. For example, teachers could use social media platforms to share relevant educational resources and facilitate online discussions. Parents could limit their children’s social media use and encourage them to prioritize their academic responsibilities. They could also engage in open communication with their children to understand their social media use and its impact on their academic performance. Policymakers could develop guidelines and policies to regulate social media use among high school students. For example, schools could implement social media policies that restrict access during class time and encourage responsible use.

References:

• Kirschner, P. A., & Karpinski, A. C. (2010). Facebook® and academic performance. Computers in Human Behavior, 26(6), 1237-1245.
• Paul, J. A., Baker, H. M., & Cochran, J. D. (2012). Effect of online social networking on student academic performance. Journal of the Research Center for Educational Technology, 8(1), 1-19.
• Pantic, I. (2014). Online social networking and mental health. Cyberpsychology, Behavior, and Social Networking, 17(10), 652-657.
• Rosen, L. D., Carrier, L. M., & Cheever, N. A. (2013). Facebook and texting made me do it: Media-induced task-switching while studying. Computers in Human Behavior, 29(3), 948-958.

Note*: Above mention, Example is just a sample for the students’ guide. Do not directly copy and paste as your College or University assignment. Kindly do some research and Write your own.

Applications of Research Report

Research reports have many applications, including:

• Communicating research findings: The primary application of a research report is to communicate the results of a study to other researchers, stakeholders, or the general public. The report serves as a way to share new knowledge, insights, and discoveries with others in the field.
• Informing policy and practice : Research reports can inform policy and practice by providing evidence-based recommendations for decision-makers. For example, a research report on the effectiveness of a new drug could inform regulatory agencies in their decision-making process.
• Supporting further research: Research reports can provide a foundation for further research in a particular area. Other researchers may use the findings and methodology of a report to develop new research questions or to build on existing research.
• Evaluating programs and interventions : Research reports can be used to evaluate the effectiveness of programs and interventions in achieving their intended outcomes. For example, a research report on a new educational program could provide evidence of its impact on student performance.
• Demonstrating impact : Research reports can be used to demonstrate the impact of research funding or to evaluate the success of research projects. By presenting the findings and outcomes of a study, research reports can show the value of research to funders and stakeholders.
• Enhancing professional development : Research reports can be used to enhance professional development by providing a source of information and learning for researchers and practitioners in a particular field. For example, a research report on a new teaching methodology could provide insights and ideas for educators to incorporate into their own practice.

How to write Research Report

Here are some steps you can follow to write a research report:

• Identify the research question: The first step in writing a research report is to identify your research question. This will help you focus your research and organize your findings.
• Conduct research : Once you have identified your research question, you will need to conduct research to gather relevant data and information. This can involve conducting experiments, reviewing literature, or analyzing data.
• Organize your findings: Once you have gathered all of your data, you will need to organize your findings in a way that is clear and understandable. This can involve creating tables, graphs, or charts to illustrate your results.
• Write the report: Once you have organized your findings, you can begin writing the report. Start with an introduction that provides background information and explains the purpose of your research. Next, provide a detailed description of your research methods and findings. Finally, summarize your results and draw conclusions based on your findings.
• Proofread and edit: After you have written your report, be sure to proofread and edit it carefully. Check for grammar and spelling errors, and make sure that your report is well-organized and easy to read.
• Include a reference list: Be sure to include a list of references that you used in your research. This will give credit to your sources and allow readers to further explore the topic if they choose.
• Format your report: Finally, format your report according to the guidelines provided by your instructor or organization. This may include formatting requirements for headings, margins, fonts, and spacing.

Purpose of Research Report

The purpose of a research report is to communicate the results of a research study to a specific audience, such as peers in the same field, stakeholders, or the general public. The report provides a detailed description of the research methods, findings, and conclusions.

Some common purposes of a research report include:

• Sharing knowledge: A research report allows researchers to share their findings and knowledge with others in their field. This helps to advance the field and improve the understanding of a particular topic.
• Identifying trends: A research report can identify trends and patterns in data, which can help guide future research and inform decision-making.
• Addressing problems: A research report can provide insights into problems or issues and suggest solutions or recommendations for addressing them.
• Evaluating programs or interventions : A research report can evaluate the effectiveness of programs or interventions, which can inform decision-making about whether to continue, modify, or discontinue them.
• Meeting regulatory requirements: In some fields, research reports are required to meet regulatory requirements, such as in the case of drug trials or environmental impact studies.

When to Write Research Report

A research report should be written after completing the research study. This includes collecting data, analyzing the results, and drawing conclusions based on the findings. Once the research is complete, the report should be written in a timely manner while the information is still fresh in the researcher’s mind.

In academic settings, research reports are often required as part of coursework or as part of a thesis or dissertation. In this case, the report should be written according to the guidelines provided by the instructor or institution.

In other settings, such as in industry or government, research reports may be required to inform decision-making or to comply with regulatory requirements. In these cases, the report should be written as soon as possible after the research is completed in order to inform decision-making in a timely manner.

Overall, the timing of when to write a research report depends on the purpose of the research, the expectations of the audience, and any regulatory requirements that need to be met. However, it is important to complete the report in a timely manner while the information is still fresh in the researcher’s mind.

Characteristics of Research Report

There are several characteristics of a research report that distinguish it from other types of writing. These characteristics include:

• Objective: A research report should be written in an objective and unbiased manner. It should present the facts and findings of the research study without any personal opinions or biases.
• Systematic: A research report should be written in a systematic manner. It should follow a clear and logical structure, and the information should be presented in a way that is easy to understand and follow.
• Detailed: A research report should be detailed and comprehensive. It should provide a thorough description of the research methods, results, and conclusions.
• Accurate : A research report should be accurate and based on sound research methods. The findings and conclusions should be supported by data and evidence.
• Organized: A research report should be well-organized. It should include headings and subheadings to help the reader navigate the report and understand the main points.
• Clear and concise: A research report should be written in clear and concise language. The information should be presented in a way that is easy to understand, and unnecessary jargon should be avoided.
• Citations and references: A research report should include citations and references to support the findings and conclusions. This helps to give credit to other researchers and to provide readers with the opportunity to further explore the topic.

Advantages of Research Report

Research reports have several advantages, including:

• Communicating research findings: Research reports allow researchers to communicate their findings to a wider audience, including other researchers, stakeholders, and the general public. This helps to disseminate knowledge and advance the understanding of a particular topic.
• Providing evidence for decision-making : Research reports can provide evidence to inform decision-making, such as in the case of policy-making, program planning, or product development. The findings and conclusions can help guide decisions and improve outcomes.
• Supporting further research: Research reports can provide a foundation for further research on a particular topic. Other researchers can build on the findings and conclusions of the report, which can lead to further discoveries and advancements in the field.
• Demonstrating expertise: Research reports can demonstrate the expertise of the researchers and their ability to conduct rigorous and high-quality research. This can be important for securing funding, promotions, and other professional opportunities.
• Meeting regulatory requirements: In some fields, research reports are required to meet regulatory requirements, such as in the case of drug trials or environmental impact studies. Producing a high-quality research report can help ensure compliance with these requirements.

Limitations of Research Report

Despite their advantages, research reports also have some limitations, including:

• Time-consuming: Conducting research and writing a report can be a time-consuming process, particularly for large-scale studies. This can limit the frequency and speed of producing research reports.
• Expensive: Conducting research and producing a report can be expensive, particularly for studies that require specialized equipment, personnel, or data. This can limit the scope and feasibility of some research studies.
• Limited generalizability: Research studies often focus on a specific population or context, which can limit the generalizability of the findings to other populations or contexts.
• Potential bias : Researchers may have biases or conflicts of interest that can influence the findings and conclusions of the research study. Additionally, participants may also have biases or may not be representative of the larger population, which can limit the validity and reliability of the findings.
• Accessibility: Research reports may be written in technical or academic language, which can limit their accessibility to a wider audience. Additionally, some research may be behind paywalls or require specialized access, which can limit the ability of others to read and use the findings.

About the author

Muhammad Hassan

Researcher, Academic Writer, Web developer

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Section 1- Evidence-based practice (EBP)

Chapter 6: Components of a Research Report

Components of a research report.

Partido, B.B.

Elements of  research report

The research report contains four main areas:

• Introduction – What is the issue? What is known? What is not known? What are you trying to find out? This sections ends with the purpose and specific aims of the study.
• Methods – The recipe for the study. If someone wanted to perform the same study, what information would they need? How will you answer your research question? This part usually contains subheadings: Participants, Instruments, Procedures, Data Analysis,
• Results – What was found? This is organized by specific aims and provides the results of the statistical analysis.
• Discussion – How do the results fit in with the existing  literature? What were the limitations and areas of future research?

Formalized Curiosity for Knowledge and Innovation Copyright © by partido1. All Rights Reserved.

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Home Market Research

Research Reports: Definition and How to Write Them

Reports are usually spread across a vast horizon of topics but are focused on communicating information about a particular topic and a niche target market. The primary motive of research reports is to convey integral details about a study for marketers to consider while designing new strategies.

Certain events, facts, and other information based on incidents need to be relayed to the people in charge, and creating research reports is the most effective communication tool. Ideal research reports are extremely accurate in the offered information with a clear objective and conclusion. These reports should have a clean and structured format to relay information effectively.

What are Research Reports?

Research reports are recorded data prepared by researchers or statisticians after analyzing the information gathered by conducting organized research, typically in the form of surveys or qualitative methods .

A research report is a reliable source to recount details about a conducted research. It is most often considered to be a true testimony of all the work done to garner specificities of research.

The various sections of a research report are:

• Background/Introduction
• Implemented Methods
• Results based on Analysis
• Deliberation

Learn more: Quantitative Research

Components of Research Reports

Research is imperative for launching a new product/service or a new feature. The markets today are extremely volatile and competitive due to new entrants every day who may or may not provide effective products. An organization needs to make the right decisions at the right time to be relevant in such a market with updated products that suffice customer demands.

The details of a research report may change with the purpose of research but the main components of a report will remain constant. The research approach of the market researcher also influences the style of writing reports. Here are seven main components of a productive research report:

• Research Report Summary: The entire objective along with the overview of research are to be included in a summary which is a couple of paragraphs in length. All the multiple components of the research are explained in brief under the report summary.  It should be interesting enough to capture all the key elements of the report.
• Research Introduction: There always is a primary goal that the researcher is trying to achieve through a report. In the introduction section, he/she can cover answers related to this goal and establish a thesis which will be included to strive and answer it in detail.  This section should answer an integral question: “What is the current situation of the goal?”.  After the research design was conducted, did the organization conclude the goal successfully or they are still a work in progress –  provide such details in the introduction part of the research report.
• Research Methodology: This is the most important section of the report where all the important information lies. The readers can gain data for the topic along with analyzing the quality of provided content and the research can also be approved by other market researchers . Thus, this section needs to be highly informative with each aspect of research discussed in detail.  Information needs to be expressed in chronological order according to its priority and importance. Researchers should include references in case they gained information from existing techniques.
• Research Results: A short description of the results along with calculations conducted to achieve the goal will form this section of results. Usually, the exposition after data analysis is carried out in the discussion part of the report.

Learn more: Quantitative Data

• Research Discussion: The results are discussed in extreme detail in this section along with a comparative analysis of reports that could probably exist in the same domain. Any abnormality uncovered during research will be deliberated in the discussion section.  While writing research reports, the researcher will have to connect the dots on how the results will be applicable in the real world.
• Research References and Conclusion: Conclude all the research findings along with mentioning each and every author, article or any content piece from where references were taken.

Learn more: Qualitative Observation

15 Tips for Writing Research Reports

Writing research reports in the manner can lead to all the efforts going down the drain. Here are 15 tips for writing impactful research reports:

• Prepare the context before starting to write and start from the basics:  This was always taught to us in school – be well-prepared before taking a plunge into new topics. The order of survey questions might not be the ideal or most effective order for writing research reports. The idea is to start with a broader topic and work towards a more specific one and focus on a conclusion or support, which a research should support with the facts.  The most difficult thing to do in reporting, without a doubt is to start. Start with the title, the introduction, then document the first discoveries and continue from that. Once the marketers have the information well documented, they can write a general conclusion.
• Keep the target audience in mind while selecting a format that is clear, logical and obvious to them:  Will the research reports be presented to decision makers or other researchers? What are the general perceptions around that topic? This requires more care and diligence. A researcher will need a significant amount of information to start writing the research report. Be consistent with the wording, the numbering of the annexes and so on. Follow the approved format of the company for the delivery of research reports and demonstrate the integrity of the project with the objectives of the company.
• Have a clear research objective: A researcher should read the entire proposal again, and make sure that the data they provide contributes to the objectives that were raised from the beginning. Remember that speculations are for conversations, not for research reports, if a researcher speculates, they directly question their own research.
• Establish a working model:  Each study must have an internal logic, which will have to be established in the report and in the evidence. The researchers’ worst nightmare is to be required to write research reports and realize that key questions were not included.

Learn more: Quantitative Observation

• Gather all the information about the research topic. Who are the competitors of our customers? Talk to other researchers who have studied the subject of research, know the language of the industry. Misuse of the terms can discourage the readers of research reports from reading further.
• Read aloud while writing. While reading the report, if the researcher hears something inappropriate, for example, if they stumble over the words when reading them, surely the reader will too. If the researcher can’t put an idea in a single sentence, then it is very long and they must change it so that the idea is clear to everyone.
• Check grammar and spelling. Without a doubt, good practices help to understand the report. Use verbs in the present tense. Consider using the present tense, which makes the results sound more immediate. Find new words and other ways of saying things. Have fun with the language whenever possible.
• Discuss only the discoveries that are significant. If some data are not really significant, do not mention them. Remember that not everything is truly important or essential within research reports.

Learn more: Qualitative Data

• Try and stick to the survey questions. For example, do not say that the people surveyed “were worried” about an research issue , when there are different degrees of concern.
• The graphs must be clear enough so that they understand themselves. Do not let graphs lead the reader to make mistakes: give them a title, include the indications, the size of the sample, and the correct wording of the question.
• Be clear with messages. A researcher should always write every section of the report with an accuracy of details and language.
• Be creative with titles – Particularly in segmentation studies choose names “that give life to research”. Such names can survive for a long time after the initial investigation.
• Create an effective conclusion: The conclusion in the research reports is the most difficult to write, but it is an incredible opportunity to excel. Make a precise summary. Sometimes it helps to start the conclusion with something specific, then it describes the most important part of the study, and finally, it provides the implications of the conclusions.
• Get a couple more pair of eyes to read the report. Writers have trouble detecting their own mistakes. But they are responsible for what is presented. Ensure it has been approved by colleagues or friends before sending the find draft out.

Learn more: Market Research and Analysis

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Research reports

This resource will help you identify the common elements and basic format of a research report.

Research reports generally follow a similar structure and have common elements, each with a particular purpose. Learn more about each of these elements below.

Common elements of reports

Your title should be brief, topic-specific, and informative, clearly indicating the purpose and scope of your study. Include key words in your title so that search engines can easily access your work. For example:  Measurement of water around Station Pier.

An abstract is a concise summary that helps readers to quickly assess the content and direction of your paper. It should be brief, written in a single paragraph and cover: the scope and purpose of your report; an overview of methodology; a summary of the main findings or results; principal conclusions or significance of the findings; and recommendations made.

The information in the abstract must be presented in the same order as it is in your report. The abstract is usually written last when you have developed your arguments and synthesised the results.

The introduction creates the context for your research. It should provide sufficient background to allow the reader to understand and evaluate your study without needing to refer to previous publications. After reading the introduction your reader should understand exactly what your research is about, what you plan to do, why you are undertaking this research and which methods you have used. Introductions generally include:

• The rationale for the present study. Why are you interested in this topic? Why is this topic worth investigating?
• Key terms and definitions.
• An outline of the research questions and hypotheses; the assumptions or propositions that your research will test.

Not all research reports have a separate literature review section. In shorter research reports, the review is usually part of the Introduction.

A literature review is a critical survey of recent relevant research in a particular field. The review should be a selection of carefully organised, focused and relevant literature that develops a narrative ‘story’ about your topic. Your review should answer key questions about the literature:

• What is the current state of knowledge on the topic?
• What differences in approaches / methodologies are there?
• Where are the strengths and weaknesses of the research?
• What further research is needed? The review may identify a gap in the literature which provides a rationale for your study and supports your research questions and methodology.

The review is not just a summary of all you have read. Rather, it must develop an argument or a point of view that supports your chosen methodology and research questions.

The purpose of this section is to detail how you conducted your research so that others can understand and replicate your approach.

You need to briefly describe the subjects (if appropriate), any equipment or materials used and the approach taken. If the research method or method of data analysis is commonly used within your field of study, then simply reference the procedure. If, however, your methods are new or controversial then you need to describe them in more detail and provide a rationale for your approach. The methodology is written in the past tense and should be as concise as possible.

This section is a concise, factual summary of your findings, listed under headings appropriate to your research questions. It’s common to use tables and graphics. Raw data or details about the method of statistical analysis used should be included in the Appendices.

Present your results in a consistent manner. For example, if you present the first group of results as percentages, it will be confusing for the reader and difficult to make comparisons of data if later results are presented as fractions or as decimal values.

In general, you won’t discuss your results here. Any analysis of your results usually occurs in the Discussion section.

Notes on visual data representation:

• Graphs and tables may be used to reveal trends in your data, but they must be explained and referred to in adjacent accompanying text.
• Figures and tables do not simply repeat information given in the text: they summarise, amplify or complement it.
• Graphs are always referred to as ‘Figures’, and both axes must be clearly labelled.
• Tables must be numbered, and they must be able to stand-alone or make sense without your reader needing to read all of the accompanying text.

The Discussion responds to the hypothesis or research question. This section is where you interpret your results, account for your findings and explain their significance within the context of other research. Consider the adequacy of your sampling techniques, the scope and long-term implications of your study, any problems with data collection or analysis and any assumptions on which your study was based. This is also the place to discuss any disappointing results and address limitations.

Checklist for the discussion

• To what extent was each hypothesis supported?
• To what extent are your findings validated or supported by other research?
• Were there unexpected variables that affected your results?
• On reflection, was your research method appropriate?
• Can you account for any differences between your results and other studies?

Conclusions in research reports are generally fairly short and should follow on naturally from points raised in the Discussion. In this section you should discuss the significance of your findings. To what extent and in what ways are your findings useful or conclusive? Is further research required? If so, based on your research experience, what suggestions could you make about improvements to the scope or methodology of future studies?

Also, consider the practical implications of your results and any recommendations you could make. For example, if your research is on reading strategies in the primary school classroom, what are the implications of your results for the classroom teacher? What recommendations could you make for teachers?

A Reference List contains all the resources you have cited in your work, while a Bibliography is a wider list containing all the resources you have consulted (but not necessarily cited) in the preparation of your work. It is important to check which of these is required, and the preferred format, style of references and presentation requirements of your own department.

Appendices (singular ‘Appendix’) provide supporting material to your project. Examples of such materials include:

• Relevant letters to participants and organisations (e.g. regarding the ethics or conduct of the project).
• Background reports.
• Detailed calculations.

Different types of data are presented in separate appendices. Each appendix must be titled, labelled with a number or letter, and referred to in the body of the report.

Appendices are placed at the end of a report, and the contents are generally not included in the word count.

Fi nal ti p

While there are many common elements to research reports, it’s always best to double check the exact requirements for your task. You may find that you don’t need some sections, can combine others or have specific requirements about referencing, formatting or word limits.

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Report writing

• Introduction

What is a report?

What makes a successful report, how are reports read, checklist for successful reports.

• Types of Report
• Structuring your report
• Writing up your report

Useful links for report writing

• Study Advice Helping students to achieve study success with guides, video tutorials, seminars and one-to-one advice sessions.
• Maths Support A guide to Maths Support resources which may help if you're finding any mathematical or statistical topic difficult during the transition to University study.

• Academic Phrasebank Use this site for examples of linking phrases and ways to refer to sources.
• Academic writing LibGuide Expert guidance on punctuation, grammar, writing style and proof-reading.
• Reading and notemaking LibGuide Expert guidance on managing your reading and making effective notes.
• Guide to citing references Includes guidance on why, when and how to use references correctly in your academic writing.

Students often ask, "What's the difference between an essay and a report?" It can be confusing because university assignments can mix the features of both (e.g. an essay that allows sub-headings) and some assignments may not officially be called a report, but seem very "report-like" in their structure and criteria.

The guidance on this page will explain some of the key differences between essays and reports, and how the main features of reports make them economical to read. Understanding how reports are read and the features that make them effective will help you in any report-style assignment.

A report is a piece of informative writing that describes a set of actions and analyses any results in response to a specific brief. A quick definition might be: "This is what I did and this is what it means." You may be given an assignment which is not called a report but shares many of the same features; if so, aspects of this guide will be helpful.

It may help to know some of the key differences between reports and essays:

• Badly structured
• Inappropriate writing style
• Incorrect or inadequate referencing
• Doesn't answer the brief
• Too much/too little/irrelevant material
• Expression not clear
• Doesn't relate results to purpose
• Unnecessary use of jargon

How can you make sure your report does what it's meant to do, and does it well?

Make sure you know which sections your report should have and what should go in each . Reports for different disciplines and briefs will require different sections: for instance, a business report may need a separate Recommendations section but no Methods section. Check your brief carefully to make sure you have the correct sections. See the page on 'Structuring your report' in this guide to learn more about what goes where.

Remember that reports are meant to be informative : to tell the reader what was done, what was discovered as a consequence and how this relates to the reasons the report was undertaken. Include only relevant material in your background and discussion.

A report is an act of communication between you and your reader. So  pay special attention to your projected reader , and what they want from the report. Sometimes you will be asked to write for an imaginary reader (e.g. a business client). In this case it's vital to think about why they want the report to be produced (e.g. to decide on the viability of a project) and to make sure you respond to that. If it's your tutor, they will want to know that you can communicate the processes and results of your research clearly and accurately, and can discuss your findings in the context of the overall purpose.

Write simply and appropriately . Your method and findings should be described accurately and in non-ambiguous terms. A perfectly described method section would make it possible for someone else to replicate your research process and achieve the same results. See the page in this guide on 'Writing up your report' for more on this.

Spend time on your discussion section . This is the bit that pulls the whole piece together by showing how your findings relate to the purpose of the report, and to any previous research.

Every idea and piece of information you use that comes from someone else's work  must be acknowledged with a reference . Check your brief, or department handbook for the form of referencing required (usually a short reference in the body of the text, and a full reference in the Reference List at the end).

Be clear about the scope of the report . The word count will help you to understand this. For instance, a 5000 word report will be expected to include a lot more background and discussion than a 1000 word report - this will be looking for more conciseness in the way you convey your information.

This is not to suggest that you should spend less time on writing up your findings. But it does show that the sections you may think of as less important (like the  abstract or introduction ) are actually often the places a reader gets their first impressions. So it's worth getting them right.

• Does it answer the needs of the projected reader?
• Has the material been placed in the appropriate sections?
• Has all the material been checked for accuracy?
• Are graphs and tables carefully labelled?
• Is data in graphs or tables also explained in words and analysed?
• Does the discussion/conclusion show how the results relate to objectives set out in the introduction?
• Has all irrelevant material been removed?
• Is it written throughout in appropriate style (i.e. no colloquialisms or contractions, using an objective tone, specific rather than vague)?
• Is it jargon-free and clearly written?
• Has every idea taken from or inspired by someone else's work been acknowledged with a reference?
• Have all illustrations and figures taken from someone else's work been cited correctly?
• Has it been carefully proof-read to eliminate careless mistakes?
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• Last Updated: Jan 29, 2024 11:27 AM
• URL: https://libguides.reading.ac.uk/reports

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Chapter Nine: Unique features of qualitative research

What is it like to be a young man entering adulthood? According to sociologist Michael Kimmel, they are “totally confused,” “cannot commit to their relationships, work, or lives,” and are “obsessed with never wanting to grow up.” [1]   If that sounds like a bunch of malarkey to you, hold on a minute. Kimmel (2008) interviewed 400 young men, ages 16 to 26, over the course of four years across the United States to learn how young men made the transition from adolescence into adulthood. Since the results of Kimmel’s research were published in 2008, his book Guyland made quite a splash. Whatever your take on Kimmel’s research, one thing remains true—we surely would not know nearly as much as we now do about the lives of many young American men were it not for qualitative interview research.

Chapter Outline

• 9.1 Qualitative research: What is it and when should it be used?
• 9.2 Qualitative interviews
• 9.3 Issues to consider for all interview types
• 9.4 Types of Qualitative Research Designs
• 9.5 Spotlight on UTA School of Social Work
• 9.6 Analyzing qualitative data

Content Advisory

This chapter discusses or mentions the following topics: childfree adults, sexual harassment, juvenile delinquency, drunk driving, racist hate groups, ageism, sexism, police interviews, and mental health policy for children and adolescents.

• 1. These quotes come from a summary of reviews on the website dedicated to Kimmel’s book, Guyland ↵

Foundations of Social Work Research Copyright © 2020 by Rebecca L. Mauldin is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License , except where otherwise noted.

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Features of Report Writing: A Brief Overview

Features of Report Writing explores key elements like clarity, accuracy, objectivity, structure, visual aids, evidence, and recommendations. These features ensure effective communication by presenting information, substantiating claims with credible evidence, and providing actionable recommendations.

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Table of Contents  

1) What is Report Writing? 

2) Features of Report Writing 

     a) Clarity  

     b) Accuracy  

     c) Visual aids  

     d) Evidence  

     e) Structure  

     f) Recommendations  

     g) Objectivity 

3) Steps to write a Report 

4) Conclusion 

What is Report Writing ?  

Report Writing is a systematic and structured process of gathering, analysing, and presenting information in a formal document. It is a vital communication tool used across various fields, including academia, business, government, and research. Reports serve the purpose of informing, analysing, and making recommendations based on gathered data and research findings .   

The process typically involves:  

a) Defining the purpose and scope of the Report 

b) Conducting thorough research 

c) Organising the collected data 

d) Presenting the information clearly and concisely 

Reports can vary in complexity, from simple one-page documents to extensive research papers, business proposals, or technical manuals. Effective Report Writing requires a keen understanding of the target audience, as well as the ability to convey complex ideas understandably .   

It involves structuring the content logically, ensuring coherence and consistency, and providing evidence-based conclusions or recommendations. Well-written Reports facilitate informed decision-making, problem-solving, and knowledge dissemination within organisations, making them invaluable tools for conveying critical information and contributing to the overall success of various endeavours. 

Features of Report Writing  

To help you create an effective Report, here are some of its Features of Report Writing:  

Clarity  

Clarity in Report Writing is crucial. It ensures that complex ideas and data are presented straightforwardly and understandably. A clear Report leaves no room for ambiguity, allowing readers to grasp the information effortlessly. Achieving clarity involves:  

a) Using simple and precise language 

b) Structuring sentences and paragraphs logically 

c) Employing visuals like charts or graphs for better comprehension 

When a Report is clear, readers can quickly discern the key points, making it an effective tool for conveying information, aiding decision-making, and facilitating meaningful communication in various professional and academic contexts. 

Accuracy   

Accuracy is a pivotal feature in Report Writing, ensuring the information presented is precise, reliable, and error-free. It demands thorough research, attention to detail, and fact-checking to substantiate claims and findings. Inaccurate data can mislead readers and compromise the Report's credibility .   

Writers must verify sources, use reliable data collection methods, and cross-verify information to maintain the Report's accuracy. Precision in language, adherence to established methodologies, and rigorous analysis contribute to the overall accuracy of the Report. A meticulously accurate Report enhances its reliability and builds trust, making it an invaluable tool for informed decision-making and academic discourse. 

Visual aids  

Visual aids are essential components of effective Report Writing, enhancing understanding and retention of information. Graphs, charts, tables, and images simplify complex data, making it accessible to a broad audience. These visuals provide a clear visual representation of trends, comparisons, and patterns, supplementing textual information.   

They are potent tools for emphasising key points, supporting arguments, and enhancing comprehension. Well-designed visuals make the Report visually appealing and help readers absorb information more efficiently. By presenting data visually, Report writers can engage their audience, simplify complex concepts, and reinforce the main ideas, ensuring the Report's message is communicated effectively.  

Evidence  

Evidence in Report Writing refers to factual data, examples, or expert opinions supporting the document's claims and conclusions. It serves as the foundation upon which reliable arguments and analyses are built. Strong evidence enhances the Report's credibility, persuading readers of the validity of the presented information.   

Researchers often rely on empirical studies, statistical data, surveys, or credible sources to substantiate their findings. They have correctly cited evidence not only validates the Report's assertions but also demonstrates the writer's thorough research and expertise on the topic. Evidence strengthens the Report's integrity, assuring readers that the information presented is well-grounded and trustworthy.    

Structure  

Structure in Report Writing refers to the organised framework that guides the presentation of information. A well-defined structure ensures logical flow, enabling readers to navigate the content seamlessly. It typically includes sections such as introduction, methodology, findings, analysis, conclusions, and recommendations.   

Each section has a specific purpose, contributing to the overall coherence of the Report. The structure provides a roadmap for the writer, ensuring that essential points are covered systematically. Clear headings and subheadings delineate different topics, enhancing readability. A structured Report improves comprehension and reflects the writer's professionalism and attention to detail, making the document more impactful and persuasive to its intended audience. 

Recommendations  

Recommendations in Report Writing are crucial suggestions based on the findings and analysis. These actionable insights offer practical solutions, strategies, or actions that address the issues highlighted in the Report. Recommendations are grounded in evidence, making them credible and valuable for decision-makers.    

Well-crafted recommendations are specific, feasible, and tailored to the context, providing a clear pathway for implementing changes or improvements. They serve as a guide for stakeholders, helping them make informed choices and take adequate measures. The quality and relevance of recommendations often determine the Report's impact, as they empower organisations and individuals to make positive changes based on the Report's insights. 

Objectivity  

Objectivity in Report Writing refers to presenting information and analysis in an unbiased, impartial, and fair manner. It demands writers separate personal opinions or emotions from presenting facts and findings. Objective Reports rely on empirical evidence, verifiable data, and expert opinions, ensuring the content is reliable and credible.   

By maintaining objectivity, the writer establishes trust with the readers, enabling them to form opinions based on the presented information. Objectivity is essential in research and professional contexts, allowing for an accurate representation of reality and fostering a balanced, rational discussion of the topic.  

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Steps to write a Report  

Writing a comprehensive Report involves structured steps that ensure the document is well-organised, informative, and coherent. Here's a detailed overview of the essential steps to write a Report: 

a) Define purpose : Clarify the Report's objectives and scope. 

b) Research : Gather relevant information from credible sources.  

c) Organise : Structure the Report with clear sections and headings. 

d) Write introduction : Provide context, purpose, and research questions. 

e) Methodology : Explain research methods and data collection processes.  

f) Present findings : Display data using visuals, charts, or tables.  

g) Analysis : Interpret results, discuss trends, and draw connections. 

h) Conclusions : Summarise critical points, answering research questions.  

i) Recommendations : Suggest actionable solutions based on findings.  

j) Edit and proofread : Revise for clarity, coherence, and accuracy.  

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Conclusion  

Understanding the art of Report Writing is essential for effective communication. There are some Features of Report Writing which, when followed, can be efficiently prepared. These features include following a structured approach, defining clear objectives, conducting thorough research, and presenting findings logically and objectively. 

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Organizing Your Social Sciences Research Paper

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Academic writing refers to a style of expression that researchers use to define the intellectual boundaries of their disciplines and specific areas of expertise. Characteristics of academic writing include a formal tone, use of the third-person rather than first-person perspective (usually), a clear focus on the research problem under investigation, and precise word choice. Like specialist languages adopted in other professions, such as, law or medicine, academic writing is designed to convey agreed meaning about complex ideas or concepts within a community of scholarly experts and practitioners.

Academic Writing. Writing Center. Colorado Technical College; Hartley, James. Academic Writing and Publishing: A Practical Guide . New York: Routledge, 2008; Ezza, El-Sadig Y. and Touria Drid. T eaching Academic Writing as a Discipline-Specific Skill in Higher Education . Hershey, PA: IGI Global, 2020.

Importance of Good Academic Writing

The accepted form of academic writing in the social sciences can vary considerable depending on the methodological framework and the intended audience. However, most college-level research papers require careful attention to the following stylistic elements:

I.  The Big Picture Unlike creative or journalistic writing, the overall structure of academic writing is formal and logical. It must be cohesive and possess a logically organized flow of ideas; this means that the various parts are connected to form a unified whole. There should be narrative links between sentences and paragraphs so that the reader is able to follow your argument. The introduction should include a description of how the rest of the paper is organized and all sources are properly cited throughout the paper.

II.  Tone The overall tone refers to the attitude conveyed in a piece of writing. Throughout your paper, it is important that you present the arguments of others fairly and with an appropriate narrative tone. When presenting a position or argument that you disagree with, describe this argument accurately and without loaded or biased language. In academic writing, the author is expected to investigate the research problem from an authoritative point of view. You should, therefore, state the strengths of your arguments confidently, using language that is neutral, not confrontational or dismissive.

III.  Diction Diction refers to the choice of words you use. Awareness of the words you use is important because words that have almost the same denotation [dictionary definition] can have very different connotations [implied meanings]. This is particularly true in academic writing because words and terminology can evolve a nuanced meaning that describes a particular idea, concept, or phenomenon derived from the epistemological culture of that discipline [e.g., the concept of rational choice in political science]. Therefore, use concrete words [not general] that convey a specific meaning. If this cannot be done without confusing the reader, then you need to explain what you mean within the context of how that word or phrase is used within a discipline.

IV.  Language The investigation of research problems in the social sciences is often complex and multi- dimensional . Therefore, it is important that you use unambiguous language. Well-structured paragraphs and clear topic sentences enable a reader to follow your line of thinking without difficulty. Your language should be concise, formal, and express precisely what you want it to mean. Do not use vague expressions that are not specific or precise enough for the reader to derive exact meaning ["they," "we," "people," "the organization," etc.], abbreviations like 'i.e.'  ["in other words"], 'e.g.' ["for example"], or 'a.k.a.' ["also known as"], and the use of unspecific determinate words ["super," "very," "incredible," "huge," etc.].

V.  Punctuation Scholars rely on precise words and language to establish the narrative tone of their work and, therefore, punctuation marks are used very deliberately. For example, exclamation points are rarely used to express a heightened tone because it can come across as unsophisticated or over-excited. Dashes should be limited to the insertion of an explanatory comment in a sentence, while hyphens should be limited to connecting prefixes to words [e.g., multi-disciplinary] or when forming compound phrases [e.g., commander-in-chief]. Finally, understand that semi-colons represent a pause that is longer than a comma, but shorter than a period in a sentence. In general, there are four grammatical uses of semi-colons: when a second clause expands or explains the first clause; to describe a sequence of actions or different aspects of the same topic; placed before clauses which begin with "nevertheless", "therefore", "even so," and "for instance”; and, to mark off a series of phrases or clauses which contain commas. If you are not confident about when to use semi-colons [and most of the time, they are not required for proper punctuation], rewrite using shorter sentences or revise the paragraph.

VI.  Academic Conventions Among the most important rules and principles of academic engagement of a writing is citing sources in the body of your paper and providing a list of references as either footnotes or endnotes. The academic convention of citing sources facilitates processes of intellectual discovery, critical thinking, and applying a deliberate method of navigating through the scholarly landscape by tracking how cited works are propagated by scholars over time . Aside from citing sources, other academic conventions to follow include the appropriate use of headings and subheadings, properly spelling out acronyms when first used in the text, avoiding slang or colloquial language, avoiding emotive language or unsupported declarative statements, avoiding contractions [e.g., isn't], and using first person and second person pronouns only when necessary.

VII.  Evidence-Based Reasoning Assignments often ask you to express your own point of view about the research problem. However, what is valued in academic writing is that statements are based on evidence-based reasoning. This refers to possessing a clear understanding of the pertinent body of knowledge and academic debates that exist within, and often external to, your discipline concerning the topic. You need to support your arguments with evidence from scholarly [i.e., academic or peer-reviewed] sources. It should be an objective stance presented as a logical argument; the quality of the evidence you cite will determine the strength of your argument. The objective is to convince the reader of the validity of your thoughts through a well-documented, coherent, and logically structured piece of writing. This is particularly important when proposing solutions to problems or delineating recommended courses of action.

VIII.  Thesis-Driven Academic writing is “thesis-driven,” meaning that the starting point is a particular perspective, idea, or position applied to the chosen topic of investigation, such as, establishing, proving, or disproving solutions to the questions applied to investigating the research problem. Note that a problem statement without the research questions does not qualify as academic writing because simply identifying the research problem does not establish for the reader how you will contribute to solving the problem, what aspects you believe are most critical, or suggest a method for gathering information or data to better understand the problem.

IX.  Complexity and Higher-Order Thinking Academic writing addresses complex issues that require higher-order thinking skills applied to understanding the research problem [e.g., critical, reflective, logical, and creative thinking as opposed to, for example, descriptive or prescriptive thinking]. Higher-order thinking skills include cognitive processes that are used to comprehend, solve problems, and express concepts or that describe abstract ideas that cannot be easily acted out, pointed to, or shown with images. Think of your writing this way: One of the most important attributes of a good teacher is the ability to explain complexity in a way that is understandable and relatable to the topic being presented during class. This is also one of the main functions of academic writing--examining and explaining the significance of complex ideas as clearly as possible.  As a writer, you must adopt the role of a good teacher by summarizing complex information into a well-organized synthesis of ideas, concepts, and recommendations that contribute to a better understanding of the research problem.

Academic Writing. Writing Center. Colorado Technical College; Hartley, James. Academic Writing and Publishing: A Practical Guide . New York: Routledge, 2008; Murray, Rowena  and Sarah Moore. The Handbook of Academic Writing: A Fresh Approach . New York: Open University Press, 2006; Johnson, Roy. Improve Your Writing Skills . Manchester, UK: Clifton Press, 1995; Nygaard, Lynn P. Writing for Scholars: A Practical Guide to Making Sense and Being Heard . Second edition. Los Angeles, CA: Sage Publications, 2015; Silvia, Paul J. How to Write a Lot: A Practical Guide to Productive Academic Writing . Washington, DC: American Psychological Association, 2007; Style, Diction, Tone, and Voice. Writing Center, Wheaton College; Sword, Helen. Stylish Academic Writing . Cambridge, MA: Harvard University Press, 2012.

Strategies for...

Understanding Academic Writing and Its Jargon

The very definition of research jargon is language specific to a particular community of practitioner-researchers . Therefore, in modern university life, jargon represents the specific language and meaning assigned to words and phrases specific to a discipline or area of study. For example, the idea of being rational may hold the same general meaning in both political science and psychology, but its application to understanding and explaining phenomena within the research domain of a each discipline may have subtle differences based upon how scholars in that discipline apply the concept to the theories and practice of their work.

Given this, it is important that specialist terminology [i.e., jargon] must be used accurately and applied under the appropriate conditions . Subject-specific dictionaries are the best places to confirm the meaning of terms within the context of a specific discipline. These can be found by either searching in the USC Libraries catalog by entering the disciplinary and the word dictionary [e.g., sociology and dictionary] or using a database such as Credo Reference [a curated collection of subject encyclopedias, dictionaries, handbooks, guides from highly regarded publishers] . It is appropriate for you to use specialist language within your field of study, but you should avoid using such language when writing for non-academic or general audiences.

Problems with Opaque Writing

A common criticism of scholars is that they can utilize needlessly complex syntax or overly expansive vocabulary that is impenetrable or not well-defined. When writing, avoid problems associated with opaque writing by keeping in mind the following:

1.   Excessive use of specialized terminology . Yes, it is appropriate for you to use specialist language and a formal style of expression in academic writing, but it does not mean using "big words" just for the sake of doing so. Overuse of complex or obscure words or writing complicated sentence constructions gives readers the impression that your paper is more about style than substance; it leads the reader to question if you really know what you are talking about. Focus on creating clear, concise, and elegant prose that minimizes reliance on specialized terminology.

2.   Inappropriate use of specialized terminology . Because you are dealing with concepts, research, and data within your discipline, you need to use the technical language appropriate to that area of study. However, nothing will undermine the validity of your study quicker than the inappropriate application of a term or concept. Avoid using terms whose meaning you are unsure of--do not just guess or assume! Consult the meaning of terms in specialized, discipline-specific dictionaries by searching the USC Libraries catalog or the Credo Reference database [see above].

Additional Problems to Avoid

In addition to understanding the use of specialized language, there are other aspects of academic writing in the social sciences that you should be aware of. These problems include:

• Personal nouns . Excessive use of personal nouns [e.g., I, me, you, us] may lead the reader to believe the study was overly subjective. These words can be interpreted as being used only to avoid presenting empirical evidence about the research problem. Limit the use of personal nouns to descriptions of things you actually did [e.g., "I interviewed ten teachers about classroom management techniques..."]. Note that personal nouns are generally found in the discussion section of a paper because this is where you as the author/researcher interpret and describe your work.
• Directives . Avoid directives that demand the reader to "do this" or "do that." Directives should be framed as evidence-based recommendations or goals leading to specific outcomes. Note that an exception to this can be found in various forms of action research that involve evidence-based advocacy for social justice or transformative change. Within this area of the social sciences, authors may offer directives for action in a declarative tone of urgency.
• Informal, conversational tone using slang and idioms . Academic writing relies on excellent grammar and precise word structure. Your narrative should not include regional dialects or slang terms because they can be open to interpretation. Your writing should be direct and concise using standard English.
• Wordiness. Focus on being concise, straightforward, and developing a narrative that does not have confusing language . By doing so, you  help eliminate the possibility of the reader misinterpreting the design and purpose of your study.
• Vague expressions (e.g., "they," "we," "people," "the company," "that area," etc.). Being concise in your writing also includes avoiding vague references to persons, places, or things. While proofreading your paper, be sure to look for and edit any vague or imprecise statements that lack context or specificity.
• Numbered lists and bulleted items . The use of bulleted items or lists should be used only if the narrative dictates a need for clarity. For example, it is fine to state, "The four main problems with hedge funds are:" and then list them as 1, 2, 3, 4. However, in academic writing, this must then be followed by detailed explanation and analysis of each item. Given this, the question you should ask yourself while proofreading is: why begin with a list in the first place rather than just starting with systematic analysis of each item arranged in separate paragraphs? Also, be careful using numbers because they can imply a ranked order of priority or importance. If none exists, use bullets and avoid checkmarks or other symbols.
• Descriptive writing . Describing a research problem is an important means of contextualizing a study. In fact, some description or background information may be needed because you can not assume the reader knows the key aspects of the topic. However, the content of your paper should focus on methodology, the analysis and interpretation of findings, and their implications as they apply to the research problem rather than background information and descriptions of tangential issues.
• Personal experience. Drawing upon personal experience [e.g., traveling abroad; caring for someone with Alzheimer's disease] can be an effective way of introducing the research problem or engaging your readers in understanding its significance. Use personal experience only as an example, though, because academic writing relies on evidence-based research. To do otherwise is simply story-telling.

NOTE:   Rules concerning excellent grammar and precise word structure do not apply when quoting someone.  A quote should be inserted in the text of your paper exactly as it was stated. If the quote is especially vague or hard to understand, consider paraphrasing it or using a different quote to convey the same meaning. Consider inserting the term "sic" in brackets after the quoted text to indicate that the quotation has been transcribed exactly as found in the original source, but the source had grammar, spelling, or other errors. The adverb sic informs the reader that the errors are not yours.

Academic Writing. The Writing Lab and The OWL. Purdue University; Academic Writing Style. First-Year Seminar Handbook. Mercer University; Bem, Daryl J. Writing the Empirical Journal Article. Cornell University; College Writing. The Writing Center. University of North Carolina; Murray, Rowena  and Sarah Moore. The Handbook of Academic Writing: A Fresh Approach . New York: Open University Press, 2006; Johnson, Eileen S. “Action Research.” In Oxford Research Encyclopedia of Education . Edited by George W. Noblit and Joseph R. Neikirk. (New York: Oxford University Press, 2020); Oppenheimer, Daniel M. "Consequences of Erudite Vernacular Utilized Irrespective of Necessity: Problems with Using Long Words Needlessly." Applied Cognitive Psychology 20 (2006): 139-156; Ezza, El-Sadig Y. and Touria Drid. T eaching Academic Writing as a Discipline-Specific Skill in Higher Education . Hershey, PA: IGI Global, 2020; Pernawan, Ari. Common Flaws in Students' Research Proposals. English Education Department. Yogyakarta State University; Style. College Writing. The Writing Center. University of North Carolina; Invention: Five Qualities of Good Writing. The Reading/Writing Center. Hunter College; Sword, Helen. Stylish Academic Writing . Cambridge, MA: Harvard University Press, 2012; What Is an Academic Paper? Institute for Writing Rhetoric. Dartmouth College.

Structure and Writing Style

I. Improving Academic Writing

To improve your academic writing skills, you should focus your efforts on three key areas: 1.   Clear Writing . The act of thinking about precedes the process of writing about. Good writers spend sufficient time distilling information and reviewing major points from the literature they have reviewed before creating their work. Writing detailed outlines can help you clearly organize your thoughts. Effective academic writing begins with solid planning, so manage your time carefully. 2.  Excellent Grammar . Needless to say, English grammar can be difficult and complex; even the best scholars take many years before they have a command of the major points of good grammar. Take the time to learn the major and minor points of good grammar. Spend time practicing writing and seek detailed feedback from professors. Take advantage of the Writing Center on campus if you need help. Proper punctuation and good proofreading skills can significantly improve academic writing [see sub-tab for proofreading you paper ].

Refer to these three basic resources to help your grammar and writing skills:

• A good writing reference book, such as, Strunk and White’s book, The Elements of Style or the St. Martin's Handbook ;
• A college-level dictionary, such as, Merriam-Webster's Collegiate Dictionary ;
• The latest edition of Roget's Thesaurus in Dictionary Form .

3.  Consistent Stylistic Approach . Whether your professor expresses a preference to use MLA, APA or the Chicago Manual of Style or not, choose one style manual and stick to it. Each of these style manuals provide rules on how to write out numbers, references, citations, footnotes, and lists. Consistent adherence to a style of writing helps with the narrative flow of your paper and improves its readability. Note that some disciplines require a particular style [e.g., education uses APA] so as you write more papers within your major, your familiarity with it will improve.

II. Evaluating Quality of Writing

A useful approach for evaluating the quality of your academic writing is to consider the following issues from the perspective of the reader. While proofreading your final draft, critically assess the following elements in your writing.

• It is shaped around one clear research problem, and it explains what that problem is from the outset.
• Your paper tells the reader why the problem is important and why people should know about it.
• You have accurately and thoroughly informed the reader what has already been published about this problem or others related to it and noted important gaps in the research.
• You have provided evidence to support your argument that the reader finds convincing.
• The paper includes a description of how and why particular evidence was collected and analyzed, and why specific theoretical arguments or concepts were used.
• The paper is made up of paragraphs, each containing only one controlling idea.
• You indicate how each section of the paper addresses the research problem.
• You have considered counter-arguments or counter-examples where they are relevant.
• Arguments, evidence, and their significance have been presented in the conclusion.
• Limitations of your research have been explained as evidence of the potential need for further study.
• The narrative flows in a clear, accurate, and well-organized way.

Boscoloa, Pietro, Barbara Arféb, and Mara Quarisaa. “Improving the Quality of Students' Academic Writing: An Intervention Study.” Studies in Higher Education 32 (August 2007): 419-438; Academic Writing. The Writing Lab and The OWL. Purdue University; Academic Writing Style. First-Year Seminar Handbook. Mercer University; Bem, Daryl J. Writing the Empirical Journal Article. Cornell University; Candlin, Christopher. Academic Writing Step-By-Step: A Research-based Approach . Bristol, CT: Equinox Publishing Ltd., 2016; College Writing. The Writing Center. University of North Carolina; Style . College Writing. The Writing Center. University of North Carolina; Invention: Five Qualities of Good Writing. The Reading/Writing Center. Hunter College; Sword, Helen. Stylish Academic Writing . Cambridge, MA: Harvard University Press, 2012; What Is an Academic Paper? Institute for Writing Rhetoric. Dartmouth College.

Writing Tip

Considering the Passive Voice in Academic Writing

In the English language, we are able to construct sentences in the following way: 1.  "The policies of Congress caused the economic crisis." 2.  "The economic crisis was caused by the policies of Congress."

The decision about which sentence to use is governed by whether you want to focus on “Congress” and what they did, or on “the economic crisis” and what caused it. This choice in focus is achieved with the use of either the active or the passive voice. When you want your readers to focus on the "doer" of an action, you can make the "doer"' the subject of the sentence and use the active form of the verb. When you want readers to focus on the person, place, or thing affected by the action, or the action itself, you can make the effect or the action the subject of the sentence by using the passive form of the verb.

Often in academic writing, scholars don't want to focus on who is doing an action, but on who is receiving or experiencing the consequences of that action. The passive voice is useful in academic writing because it allows writers to highlight the most important participants or events within sentences by placing them at the beginning of the sentence.

Use the passive voice when:

• You want to focus on the person, place, or thing affected by the action, or the action itself;
• It is not important who or what did the action;
• You want to be impersonal or more formal.

Form the passive voice by:

• Turning the object of the active sentence into the subject of the passive sentence.
• Changing the verb to a passive form by adding the appropriate form of the verb "to be" and the past participle of the main verb.

NOTE: Consult with your professor about using the passive voice before submitting your research paper. Some strongly discourage its use!

Active and Passive Voice. The Writing Lab and The OWL. Purdue University; Diefenbach, Paul. Future of Digital Media Syllabus. Drexel University; Passive Voice. The Writing Center. University of North Carolina.  

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What is a Marketing Research Report and How to Write It?

Table of contents

There is nothing more embarrassing for a marketer than to hear a client say “…this doesn’t quite address the business questions that we need to answer.” And unfortunately, this is a rather common occurrence in market research reporting that most marketers would care to admit.

So, why do most market research reports fail to meet client expectations? Well, in most cases, because there is more emphasis on methodology and analytic techniques used to craft the report rather than relying on data visualization, creative story-telling, and outlining actionable direction/steps.

Now, our next big question is, how do you avoid your client’s dreaded deer-in-the-headlights reaction when presenting such a report? This blog post will answer this and much more, as we go through the following:

What Is a Market Research Report?

Why is market research important, differences between primary and secondary market research, types of market research, market research reports advantages and disadvantages, how to do market research, how to prepare a market research report: 5 steps, marketing research report templates, marketing research reports best practices, bring your market research reports a step further with databox.

The purpose of creating a market research report is to make calculated decisions about business ideas. Market research is done to evaluate the feasibility of a new product or service, through research conducted with potential consumers. The information obtained from conducting market research is then documented in a formal report that should contain the following details:

• The characteristics of your ideal customers
• You customers buying habits
• The value your product or service can bring to those customers
• A list of your top competitors

Every business aims to provide the best possible product or service at the lowest cost possible. Simply said, market research is important because it helps you understand your customers and determine whether the product or service that you are about to launch is worth the effort.

Here is an example of a customer complaint that may result in more detailed market research:

Suppose you sell widgets, and you want your widget business to succeed over the long term. Over the years, you have developed many different ways of making widgets. But a couple of years ago, a customer complained that your widgets were made of a cheap kind of foam that fell apart after six months. You didn’t think at the time that this was a major problem, but now you know it.

The customer is someone you really want to keep. So, you decide to research this complaint. You set up a focus group of people who use widgets and ask them what they think about the specific problem. After the conducted survey you’ll get a better picture of customer opinions, so you can either decide to make the changes regarding widget design or just let it go.

PRO TIP: How Well Are Your Marketing KPIs Performing?

Like most marketers and marketing managers, you want to know how well your efforts are translating into results each month. How much traffic and new contact conversions do you get? How many new contacts do you get from organic sessions? How are your email campaigns performing? How well are your landing pages converting? You might have to scramble to put all of this together in a single report, but now you can have it all at your fingertips in a single Databox dashboard.

Our Marketing Overview Dashboard includes data from Google Analytics 4 and HubSpot Marketing with key performance metrics like:

• Sessions . The number of sessions can tell you how many times people are returning to your website. Obviously, the higher the better.
• New Contacts from Sessions . How well is your campaign driving new contacts and customers?
• Marketing Performance KPIs . Tracking the number of MQLs, SQLs, New Contacts and similar will help you identify how your marketing efforts contribute to sales.
• Email Performance . Measure the success of your email campaigns from HubSpot. Keep an eye on your most important email marketing metrics such as number of sent emails, number of opened emails, open rate, email click-through rate, and more.
• Blog Posts and Landing Pages . How many people have viewed your blog recently? How well are your landing pages performing?

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Marketing research requires both primary and secondary market research. But what does that mean and what are the main differences?

Primary market research takes in information directly from customers, usually as participants in surveys. Usually, it is consisted of:

• Exploratory Primary Research – This type of research helps to identify possible problem areas, and it’s not focused on discovering specific information about customers. As with any research, exploratory primary research should be conducted carefully. Researchers need to craft an interviewing or surveying plan, and gather enough respondents to ensure reasonable levels of statistical reliability.
• Specific Primary Research – This type of research is one of the best ways to approach a problem because it relies on existing customer data. Specific research provides a deeper, more thorough understanding of the problem and its potential solutions. The greatest advantage of specific research is that it lets you explore a very specific question, and focus on a specific problem or an opportunity.

Secondary market research collects information from other sources such as databases, trend reports, market or government statistics, industry content, etc. We can divide secondary market research into 3 categories:

• Public market data – Public sources range from academic journals and government reports to tax returns and court documents. These sources aren’t always easy to find. Many are available only in print in libraries and archives. You have to look beyond search engines like Google to find public source documents.
• Commercial data – Those are typically created by specialized agencies like Pew, Gartner or Forrester. the research agencies are quite expensive, but they provide a lot of useful information.
• Internal data – Your organization’s databases are gold mines for market research. In the best cases, your salespeople can tell you what they think about customers. Your salespeople are your direct sources of information about the market. Don’t underestimate your internal data.

In general, primary research is more reliable than secondary research, because researchers have to interview people directly. But primary research is expensive and time-consuming. Secondary research can be quicker and less expensive.

There are plenty of ways to conduct marketing research reports. Mostly, the type of research done will depend on your goals. Here are some types of market research often conducted by marketers.

Focus Groups

Product/service use research, observation-based research, buyer persona research, market segmentation research, pricing research, competitive analysis research, customer satisfaction and loyalty research, brand awareness research, campaign research.

An interview is an interactive process of asking and answering questions and observing your respondent’s responses. Interviews are one of the most commonly used tools in market research . An interview allows an organization to observe, in detail, how its consumers interact with its products and services. It also allows an organization to address specific questions.

A focus group is a group of people who get together to discuss a particular topic. A moderator leads the discussion and takes notes. The main benefit of focus groups is that they are quick and easy to conduct. You can gather a group of carefully-selected people, give them a product to try out, and get their feedback within a few hours/days.

Product or service use research helps you obtain useful information about your product or service such as:

• What your current customers do with the product/service
• Which features of the product/service are particularly important to your customers
• What they dislike about the product/service
• What they would change about the product/service

Observation-based research helps you to observe your target audience interacting with your product or service. You will see the interactions and which aspects work well and which could be improved. The main point is to directly experience the feedback from your target audience’s point of view.

Personas are an essential sales tool. By knowing your buyers’ pain points and the challenges they face, you can create better content, target messaging, and campaigns for them. Buyer persona research is based on market research, and it’s built around data that describes your customers’ demographics, behaviors, motivations, and concerns. Sales reporting software can significantly help you develop buyer personas when you gain insights after you collected all information.

Market segmentation research is carried out to better understand existing and potential market segments. The objective is to determine how to target different market segments and how they differ from each other. The three most important steps in writing a market segmentation research report are:

• Defining the problem
• Determining the solution [and]
• Defining the market

Related : 9 Customer Segmentation Tips to Personalize Ecommerce Marketing and Drive More Sales

A price that is too high, or too low, can kill a business. And without good market research, you don’t really know what is a good price for your product. Pricing research helps you define your pricing strategy.

In a competitive analysis, you define your “competition” as any other entity that competes with you in your market, whether you’re selling a widget or a piece of real estate. With competitive analysis research, you can find out things like:

• Who your competitors are
• What they’ve done in the past
• What’s working well for them
• Their weaknesses
• How they’re positioned in the market
• How they market themselves
• What they’re doing that you’re not

Related : How to Do an SEO Competitive Analysis: A Step-by-Step Guide

In today’s marketplace, companies are increasingly focused on customer loyalty. What your customers want is your product, but, more importantly, they want it delivered with a service that exceeds their expectations. Successful companies listen to their customers and respond accordingly. That’s why customer satisfaction and loyalty research is a critical component of that basic equation.

Related : 11 Tactics for Effectively Measuring Your Customer Service ROI

Who you are, what you stand for, what you offer, what you believe in, and what your audience thinks of you is all wrapped up in brand. Brand awareness research tells what your target audience knows about your brand and what’s their experience like.

A campaign research report is a detailed account of how your marketing campaign performed. It includes all the elements that went into creating the campaign: planning, implementation, and measurement.

Here are some of the top advantages and disadvantages of doing market research and crafting market research reports.

• Identify business opportunities – A market research report can be used to analyze potential markets and new products. It can give information about customer needs, preferences, and attitudes. Also, it compare products and services.
• A clear understanding of your customers – A market report gives company’s marketing department an in-depth picture about customers’ needs and wants. This knowledge can be used to improve products, prices, and advertising.
• Mitigates risks – 30% of small businesses fail within the first two years. Why is this so? The answer is that entrepreneurs are risk takers. However, there are risks that could be avoided. A good marketing research will help you identify those risks and allow you to mitigate them.
• Clear data-driven insights – Market research encompasses a wide range of activities, from determining market size and segment to forecasting demand, and from identifying competitors to monitoring pricing. All of these are quantified and measurable which means that gives you a clear path for building unique decisions based on numbers.

Disadvantages

• It’s not cheap – Although market research can be done for as little as $500, large markets like the United States can run into millions of dollars. If a research is done for a specific product, the budget may be even much higher. The budget also depends on the quality of the research. The more expensive it is, the more time the research will take.
• Some insights could be false – For example, if you are conducting a survey, data may be inadequate or inaccurate because respondents can, well, simply be dishonest and lie.

Here are the essential steps you need to take when doing market research:

Define your buyer persona

Identify a persona group to engage, prepare research questions for your market research participants, list your primary competitors, summarize your findings.

The job of a marketing persona is to describe your ideal customer and to tell you what they want, what motivates them, what frustrates them, and what limits them. Finding out these things means you have a better chance of designing your products, services, marketing messages, and brand around real customers. There is no one right way to create a buyer persona, though.

For example, if you’re in an industry focused on education, you could include things like:

• Educational level
• Education background

It’s recommended that you create 3-5 buyer personas for your products, based on your ideal customer.

This should be a representative sample of your target customers so you can better understand their behavior. You want to find people who fit both your target personas and who represent the broader demographic of your market. People who recently made a purchase or purposefully decided not to make one are a good sample to start with.

The questions you use determine the quality of your results. Of course, the quality of your results also depends on the quality of your participants.

Don’t ask questions that imply a yes or no answer. Instead, use open questions. For example, if you are researching customers about yogurt products, you could ask them: „ What have you heard about yogurt ?” or “ What do you think of yogurt ?“.

Avoid questions that use numbers, such as “ How many times a week do you eat yogurt ?”

Avoid questions that suggest a set of mutually exclusive answers, such as “ Do you like yogurt for breakfast, lunch, or dinner ?”

Avoid questions that imply a scale, such as “ Do you like chocolate-flavored yogurt ?”

Market researchers sometimes call one company the top competitor, another middle competitor, and the third one small competitor. However you classify them, you want to identify at least three companies in each category. Now, for each business on your list, list its key characteristics. For example, if your business sells running shoes, a key characteristic might be the product’s quality.

Next, make a list of your small business’s competitive advantages. These include the unique qualities or features of your business that make it the best choice of customers for the products or services it offers. Make a list of these competitive advantages and list them next to the key characteristics you listed for your business.

You have just finished writing your marketing research report. Everything is out there quantified or qualified. You just have to sum it up and focus on the most important details that are going to make a big impact on your decisions. Clear summary leads to a winning strategy!

Related : How to Prepare a Complete Marketing Report: The KPIs, Analysis, & Action Plan You Need

Here’s how to prepare a market research report in 5 simple steps:

Step 1: Cluster the data

Step 2: prepare an outline, step 3: mention the research methods, step 4: include visuals with narrative explanations, step 5: conclude the report with recommendations.

Your first step is to cluster all the available information into a manageable set. Clustering is the process of grouping information together in a way that emphasizes commonalities and minimizes differences. So, in market research, this will help to organize all the information you have about a product, service, or target market and identify your focus areas.

A marketing research report should be written so that other people can understand it:

• Include background information at the beginning to explain who your audience is and what problem you are trying to solve for them.
• In the body of the report, include a description of the methodology – Explain to the reader how your research was done, what was involved, and why you selected the methodology you used.
• Also in the body of the report, include the results of your market research. These may be quantitative or qualitative, but either way they should answer the questions you posed at the beginning.
• Include the executive summary – A summary of the entire report.

The market research methodology section includes details on the type of research, sample size, any limitations of the studies, research design, sample selection, data collection procedures, and statistical analyses used.

Visuals are an essential part of the presentation. Even the best-written text can be difficult to understand. Charts and graphs are easier to understand than text alone, and they help the reader see how the numbers fit the bigger picture.

But visuals are not the whole story. They are only one part of the presentation. Visuals are a cue for the reader. The narrative gives the story, not just the numbers.

Recommendations tend to follow logically from conclusions and are a response to a certain problem. The recommendation should always be relevant to the research rationale, that is, the recommendation should be based on the results of the research reported in the body of the report.

Now, let’s take a look at some dashboard reporting templates you could use to enhance your market research:

• Semrush (Position Tracking) Report

Brand Awareness Report

Sales pipeline performance report, customer success overview report, stripe (mrr & churn) report, semrush (position tracking) report template.

This free SEMRush dashboard template will help you monitor how your website’s search visibility on search engines evolves on a monthly basis. This dashboard contains all of the information you need to make changes and improve the ranking results of your business in Google Search.

This Brand Awareness Report will help you to get a sense of your brand awareness performance in Google Analytics, Google Organic Search, and Facebook. Use this dashboard to track brand awareness the same way you track other marketing campaigns.

Are your sales and marketing funnel healthy and growing? How is your sales and marketing funnel performing? What are the key conversion rates between your lifecycle stages? With a pipeline performance dashboard , you’ll get all of the answers quickly.

This Customer Success Overview Dashboard allows you to analyze how your customer service team’s responsiveness impacts your business. Use this dashboard to assess the correlation between your customer service performance and churn rate. 

This Stripe dashboard tracks your churn rate and MRR growth in real-time and shows you which customers (and how many of them) you have at any given point in time. All you have to do to get started is to connect your Stripe account.

As we said earlier, there are no strict rules when it comes to writing marketing research reports. On the other hand, you must find your focus if you want to write a report that will make a difference. Here are some best practices you should keep in mind when writing a research report.

• Objectives – The objective of a market research report is to define the problems, identify key issues, and suggest recommendations for further research. If you answer them successfully, you’re on the right way.
• Don’t worry about the format – Be creative. The report could be in a form of a PowerPoint presentation, Excel sheet, interactive dashboard or even a video. Use the format that best fits your audience, but make sure to make it easy to read.
• Include an executive summary, scorecard , or a dashboard – This is really important because time is money, and most people don’t have time to waste. So, how to put everything important in a short role? Address all of the objectives and put them in a graphic dashboard or scorecard. Also, you can write an executive summary template (heart of the report) that can be easily updated and read by managers or CEOs.
• Use storytelling –  A good story always makes a great point because it’s so memorable. Your research report results can double the effect with a catchy story.
• Keep it short – It’s not a secret that we are reading so little in the digital era. Use a lot of white space and bullet points. Too much text on a page means less focus for the reader.
• Be organized – Maintain the order of information. It’s important for the reader to navigate through the report easily. If they want to find some details or specific information it would be great to divide all sections with appropriate references.
• Methodological information – Methodological details could be boring. Include only the most important details that the reader needs to know to understand the big picture.
• Use images (or other visualizations) whenever you can – A good picture speaks for 1.000 words! If you can communicate the point visually, don’t hesitate to do it. It would be a lot easier for those who don’t like a lot of text to understand your results. But don’t push them where you can’t.
• Create readable graphs – The crown of marketing research reports is a comprehensive graph. Make sure to design precise and attractive graphs that will power up and round your story.
• Use the Appendix  – You can include all secondary information such as methodological details and other miscellaneous data in the Appendix at the end of the report.

Market research reports are all about presenting your data in an easy-to-understand way and making calculated decisions about business ideas. But this is something easier said than done.

When busy stakeholders and executives grab a report, they need something that will give them an idea of the results – the big picture that addresses company wide-business goals.

Can a PowerPoint presentation or a PDF report meet those expectations? Most likely not. But a dashboard can.

Keep in mind that even with the best market analysis in the world, your market research report won’t be actionable if you don’t present the data efficiently and in a way that everyone understands what the next steps are. Databox is your key ally in the matter.

Databox dashboards are designed to help you present your market research data with clarity – from identifying what is influencing your business, and understanding where your brand is situated in the market, to gauging the temperature of your niche or industry before a new product/service launch.

Present your research results with efficient, interactive dashboards now by signing up for a free trial .

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Qualitative Research: Characteristics, Design, Methods & Examples

Lauren McCall

MSc Health Psychology Graduate

MSc, Health Psychology, University of Nottingham

Lauren obtained an MSc in Health Psychology from The University of Nottingham with a distinction classification.

Learn about our Editorial Process

Saul Mcleod, PhD

Editor-in-Chief for Simply Psychology

BSc (Hons) Psychology, MRes, PhD, University of Manchester

Saul Mcleod, PhD., is a qualified psychology teacher with over 18 years of experience in further and higher education. He has been published in peer-reviewed journals, including the Journal of Clinical Psychology.

Olivia Guy-Evans, MSc

Associate Editor for Simply Psychology

BSc (Hons) Psychology, MSc Psychology of Education

Olivia Guy-Evans is a writer and associate editor for Simply Psychology. She has previously worked in healthcare and educational sectors.

On This Page:

“Not everything that can be counted counts, and not everything that counts can be counted“ (Albert Einstein)

Qualitative research is a process used for the systematic collection, analysis, and interpretation of non-numerical data (Punch, 2013). 

Qualitative research can be used to: (i) gain deep contextual understandings of the subjective social reality of individuals and (ii) to answer questions about experience and meaning from the participant’s perspective (Hammarberg et al., 2016).

Unlike quantitative research, which focuses on gathering and analyzing numerical data for statistical analysis, qualitative research focuses on thematic and contextual information.

Characteristics of Qualitative Research 

Reality is socially constructed.

Qualitative research aims to understand how participants make meaning of their experiences – individually or in social contexts. It assumes there is no objective reality and that the social world is interpreted (Yilmaz, 2013). 

The primacy of subject matter 

The primary aim of qualitative research is to understand the perspectives, experiences, and beliefs of individuals who have experienced the phenomenon selected for research rather than the average experiences of groups of people (Minichiello, 1990).

Variables are complex, interwoven, and difficult to measure

Factors such as experiences, behaviors, and attitudes are complex and interwoven, so they cannot be reduced to isolated variables , making them difficult to measure quantitatively.

However, a qualitative approach enables participants to describe what, why, or how they were thinking/ feeling during a phenomenon being studied (Yilmaz, 2013). 

Emic (insider’s point of view)

The phenomenon being studied is centered on the participants’ point of view (Minichiello, 1990).

Emic is used to describe how participants interact, communicate, and behave in the context of the research setting (Scarduzio, 2017).

Why Conduct Qualitative Research? 

In order to gain a deeper understanding of how people experience the world, individuals are studied in their natural setting. This enables the researcher to understand a phenomenon close to how participants experience it. 

Qualitative research allows researchers to gain an in-depth understanding, which is difficult to attain using quantitative methods. 

An in-depth understanding is attained since qualitative techniques allow participants to freely disclose their experiences, thoughts, and feelings without constraint (Tenny et al., 2022). 

This helps to further investigate and understand quantitative data by discovering reasons for the outcome of a study – answering the why question behind statistics. 

The exploratory nature of qualitative research helps to generate hypotheses that can then be tested quantitatively (Busetto et al., 2020).

To design hypotheses, theory must be researched using qualitative methods to find out what is important in order to begin research. 

For example, by conducting interviews or focus groups with key stakeholders to discover what is important to them. 

Examples of qualitative research questions include: 

• How does stress influence young adults’ behavior?
• What factors influence students’ school attendance rates in developed countries?
• How do adults interpret binge drinking in the UK?
• What are the psychological impacts of cervical cancer screening in women?
• How can mental health lessons be integrated into the school curriculum? 

Collecting Qualitative Data

There are four main research design methods used to collect qualitative data: observations, interviews,  focus groups, and ethnography.

Observations

This method involves watching and recording phenomena as they occur in nature. Observation can be divided into two types: participant and non-participant observation.

In participant observation, the researcher actively participates in the situation/events being observed.

In non-participant observation, the researcher is not an active part of the observation and tries not to influence the behaviors they are observing (Busetto et al., 2020). 

Observations can be covert (participants are unaware that a researcher is observing them) or overt (participants are aware of the researcher’s presence and know they are being observed).

However, awareness of an observer’s presence may influence participants’ behavior. 

Interviews give researchers a window into the world of a participant by seeking their account of an event, situation, or phenomenon. They are usually conducted on a one-to-one basis and can be distinguished according to the level at which they are structured (Punch, 2013). 

Structured interviews involve predetermined questions and sequences to ensure replicability and comparability. However, they are unable to explore emerging issues.

Informal interviews consist of spontaneous, casual conversations which are closer to the truth of a phenomenon. However, information is gathered using quick notes made by the researcher and is therefore subject to recall bias. 

Semi-structured interviews have a flexible structure, phrasing, and placement so emerging issues can be explored (Denny & Weckesser, 2022).

The use of probing questions and clarification can lead to a detailed understanding, but semi-structured interviews can be time-consuming and subject to interviewer bias. 

Focus groups 

Similar to interviews, focus groups elicit a rich and detailed account of an experience. However, focus groups are more dynamic since participants with shared characteristics construct this account together (Denny & Weckesser, 2022).

A shared narrative is built between participants to capture a group experience shaped by a shared context. 

The researcher takes on the role of a moderator, who will establish ground rules and guide the discussion by following a topic guide to focus the group discussions.

Typically, focus groups have 4-10 participants as a discussion can be difficult to facilitate with more than this, and this number allows everyone the time to speak.

Ethnography

Ethnography is a methodology used to study a group of people’s behaviors and social interactions in their environment (Reeves et al., 2008).

Data are collected using methods such as observations, field notes, or structured/ unstructured interviews.

The aim of ethnography is to provide detailed, holistic insights into people’s behavior and perspectives within their natural setting. In order to achieve this, researchers immerse themselves in a community or organization. 

Due to the flexibility and real-world focus of ethnography, researchers are able to gather an in-depth, nuanced understanding of people’s experiences, knowledge and perspectives that are influenced by culture and society.

In order to develop a representative picture of a particular culture/ context, researchers must conduct extensive field work. 

This can be time-consuming as researchers may need to immerse themselves into a community/ culture for a few days, or possibly a few years.

Qualitative Data Analysis Methods

Different methods can be used for analyzing qualitative data. The researcher chooses based on the objectives of their study. 

The researcher plays a key role in the interpretation of data, making decisions about the coding, theming, decontextualizing, and recontextualizing of data (Starks & Trinidad, 2007). 

Grounded theory

Grounded theory is a qualitative method specifically designed to inductively generate theory from data. It was developed by Glaser and Strauss in 1967 (Glaser & Strauss, 2017).

 This methodology aims to develop theories (rather than test hypotheses) that explain a social process, action, or interaction (Petty et al., 2012). To inform the developing theory, data collection and analysis run simultaneously. 

There are three key types of coding used in grounded theory: initial (open), intermediate (axial), and advanced (selective) coding. 

Throughout the analysis, memos should be created to document methodological and theoretical ideas about the data. Data should be collected and analyzed until data saturation is reached and a theory is developed. 

Content analysis

Content analysis was first used in the early twentieth century to analyze textual materials such as newspapers and political speeches.

Content analysis is a research method used to identify and analyze the presence and patterns of themes, concepts, or words in data (Vaismoradi et al., 2013). 

This research method can be used to analyze data in different formats, which can be written, oral, or visual. 

The goal of content analysis is to develop themes that capture the underlying meanings of data (Schreier, 2012). 

Qualitative content analysis can be used to validate existing theories, support the development of new models and theories, and provide in-depth descriptions of particular settings or experiences.

The following six steps provide a guideline for how to conduct qualitative content analysis.

• Define a Research Question : To start content analysis, a clear research question should be developed.
• Identify and Collect Data : Establish the inclusion criteria for your data. Find the relevant sources to analyze.
• Define the Unit or Theme of Analysis : Categorize the content into themes. Themes can be a word, phrase, or sentence.
• Develop Rules for Coding your Data : Define a set of coding rules to ensure that all data are coded consistently.
• Code the Data : Follow the coding rules to categorize data into themes.
• Analyze the Results and Draw Conclusions : Examine the data to identify patterns and draw conclusions in relation to your research question.

Discourse analysis

Discourse analysis is a research method used to study written/ spoken language in relation to its social context (Wood & Kroger, 2000).

In discourse analysis, the researcher interprets details of language materials and the context in which it is situated.

Discourse analysis aims to understand the functions of language (how language is used in real life) and how meaning is conveyed by language in different contexts. Researchers use discourse analysis to investigate social groups and how language is used to achieve specific communication goals.

Different methods of discourse analysis can be used depending on the aims and objectives of a study. However, the following steps provide a guideline on how to conduct discourse analysis.

• Define the Research Question : Develop a relevant research question to frame the analysis.
• Gather Data and Establish the Context : Collect research materials (e.g., interview transcripts, documents). Gather factual details and review the literature to construct a theory about the social and historical context of your study.
• Analyze the Content : Closely examine various components of the text, such as the vocabulary, sentences, paragraphs, and structure of the text. Identify patterns relevant to the research question to create codes, then group these into themes.
• Review the Results : Reflect on the findings to examine the function of the language, and the meaning and context of the discourse. 

Thematic analysis

Thematic analysis is a method used to identify, interpret, and report patterns in data, such as commonalities or contrasts. 

Although the origin of thematic analysis can be traced back to the early twentieth century, understanding and clarity of thematic analysis is attributed to Braun and Clarke (2006).

Thematic analysis aims to develop themes (patterns of meaning) across a dataset to address a research question. 

In thematic analysis, qualitative data is gathered using techniques such as interviews, focus groups, and questionnaires. Audio recordings are transcribed. The dataset is then explored and interpreted by a researcher to identify patterns. 

This occurs through the rigorous process of data familiarisation, coding, theme development, and revision. These identified patterns provide a summary of the dataset and can be used to address a research question.

Themes are developed by exploring the implicit and explicit meanings within the data. Two different approaches are used to generate themes: inductive and deductive. 

An inductive approach allows themes to emerge from the data. In contrast, a deductive approach uses existing theories or knowledge to apply preconceived ideas to the data.

Phases of Thematic Analysis

Braun and Clarke (2006) provide a guide of the six phases of thematic analysis. These phases can be applied flexibly to fit research questions and data. 

Template analysis

Template analysis refers to a specific method of thematic analysis which uses hierarchical coding (Brooks et al., 2014).

Template analysis is used to analyze textual data, for example, interview transcripts or open-ended responses on a written questionnaire.

To conduct template analysis, a coding template must be developed (usually from a subset of the data) and subsequently revised and refined. This template represents the themes identified by researchers as important in the dataset. 

Codes are ordered hierarchically within the template, with the highest-level codes demonstrating overarching themes in the data and lower-level codes representing constituent themes with a narrower focus.

A guideline for the main procedural steps for conducting template analysis is outlined below.

• Familiarization with the Data : Read (and reread) the dataset in full. Engage, reflect, and take notes on data that may be relevant to the research question.
• Preliminary Coding : Identify initial codes using guidance from the a priori codes, identified before the analysis as likely to be beneficial and relevant to the analysis.
• Organize Themes : Organize themes into meaningful clusters. Consider the relationships between the themes both within and between clusters.
• Produce an Initial Template : Develop an initial template. This may be based on a subset of the data.
• Apply and Develop the Template : Apply the initial template to further data and make any necessary modifications. Refinements of the template may include adding themes, removing themes, or changing the scope/title of themes. 
• Finalize Template : Finalize the template, then apply it to the entire dataset. 

Frame analysis

Frame analysis is a comparative form of thematic analysis which systematically analyzes data using a matrix output.

Ritchie and Spencer (1994) developed this set of techniques to analyze qualitative data in applied policy research. Frame analysis aims to generate theory from data.

Frame analysis encourages researchers to organize and manage their data using summarization.

This results in a flexible and unique matrix output, in which individual participants (or cases) are represented by rows and themes are represented by columns. 

Each intersecting cell is used to summarize findings relating to the corresponding participant and theme.

Frame analysis has five distinct phases which are interrelated, forming a methodical and rigorous framework.

• Familiarization with the Data : Familiarize yourself with all the transcripts. Immerse yourself in the details of each transcript and start to note recurring themes.
• Develop a Theoretical Framework : Identify recurrent/ important themes and add them to a chart. Provide a framework/ structure for the analysis.
• Indexing : Apply the framework systematically to the entire study data.
• Summarize Data in Analytical Framework : Reduce the data into brief summaries of participants’ accounts.
• Mapping and Interpretation : Compare themes and subthemes and check against the original transcripts. Group the data into categories and provide an explanation for them.

Preventing Bias in Qualitative Research

To evaluate qualitative studies, the CASP (Critical Appraisal Skills Programme) checklist for qualitative studies can be used to ensure all aspects of a study have been considered (CASP, 2018).

The quality of research can be enhanced and assessed using criteria such as checklists, reflexivity, co-coding, and member-checking. 

Co-coding 

Relying on only one researcher to interpret rich and complex data may risk key insights and alternative viewpoints being missed. Therefore, coding is often performed by multiple researchers.

A common strategy must be defined at the beginning of the coding process  (Busetto et al., 2020). This includes establishing a useful coding list and finding a common definition of individual codes.

Transcripts are initially coded independently by researchers and then compared and consolidated to minimize error or bias and to bring confirmation of findings. 

Member checking

Member checking (or respondent validation) involves checking back with participants to see if the research resonates with their experiences (Russell & Gregory, 2003).

Data can be returned to participants after data collection or when results are first available. For example, participants may be provided with their interview transcript and asked to verify whether this is a complete and accurate representation of their views.

Participants may then clarify or elaborate on their responses to ensure they align with their views (Shenton, 2004).

This feedback becomes part of data collection and ensures accurate descriptions/ interpretations of phenomena (Mays & Pope, 2000). 

Reflexivity in qualitative research

Reflexivity typically involves examining your own judgments, practices, and belief systems during data collection and analysis. It aims to identify any personal beliefs which may affect the research. 

Reflexivity is essential in qualitative research to ensure methodological transparency and complete reporting. This enables readers to understand how the interaction between the researcher and participant shapes the data.

Depending on the research question and population being researched, factors that need to be considered include the experience of the researcher, how the contact was established and maintained, age, gender, and ethnicity.

These details are important because, in qualitative research, the researcher is a dynamic part of the research process and actively influences the outcome of the research (Boeije, 2014). 

Reflexivity Example

Who you are and your characteristics influence how you collect and analyze data. Here is an example of a reflexivity statement for research on smoking. I am a 30-year-old white female from a middle-class background. I live in the southwest of England and have been educated to master’s level. I have been involved in two research projects on oral health. I have never smoked, but I have witnessed how smoking can cause ill health from my volunteering in a smoking cessation clinic. My research aspirations are to help to develop interventions to help smokers quit.

Establishing Trustworthiness in Qualitative Research

Trustworthiness is a concept used to assess the quality and rigor of qualitative research. Four criteria are used to assess a study’s trustworthiness: credibility, transferability, dependability, and confirmability.

Credibility in Qualitative Research

Credibility refers to how accurately the results represent the reality and viewpoints of the participants.

To establish credibility in research, participants’ views and the researcher’s representation of their views need to align (Tobin & Begley, 2004).

To increase the credibility of findings, researchers may use data source triangulation, investigator triangulation, peer debriefing, or member checking (Lincoln & Guba, 1985). 

Transferability in Qualitative Research

Transferability refers to how generalizable the findings are: whether the findings may be applied to another context, setting, or group (Tobin & Begley, 2004).

Transferability can be enhanced by giving thorough and in-depth descriptions of the research setting, sample, and methods (Nowell et al., 2017). 

Dependability in Qualitative Research

Dependability is the extent to which the study could be replicated under similar conditions and the findings would be consistent.

Researchers can establish dependability using methods such as audit trails so readers can see the research process is logical and traceable (Koch, 1994).

Confirmability in Qualitative Research

Confirmability is concerned with establishing that there is a clear link between the researcher’s interpretations/ findings and the data.

Researchers can achieve confirmability by demonstrating how conclusions and interpretations were arrived at (Nowell et al., 2017).

This enables readers to understand the reasoning behind the decisions made. 

Audit Trails in Qualitative Research

An audit trail provides evidence of the decisions made by the researcher regarding theory, research design, and data collection, as well as the steps they have chosen to manage, analyze, and report data. 

The researcher must provide a clear rationale to demonstrate how conclusions were reached in their study.

A clear description of the research path must be provided to enable readers to trace through the researcher’s logic (Halpren, 1983).

Researchers should maintain records of the raw data, field notes, transcripts, and a reflective journal in order to provide a clear audit trail. 

Discovery of unexpected data

Open-ended questions in qualitative research mean the researcher can probe an interview topic and enable the participant to elaborate on responses in an unrestricted manner.

This allows unexpected data to emerge, which can lead to further research into that topic. 

Flexibility

Data collection and analysis can be modified and adapted to take the research in a different direction if new ideas or patterns emerge in the data.

This enables researchers to investigate new opportunities while firmly maintaining their research goals. 

Naturalistic settings

The behaviors of participants are recorded in real-world settings. Studies that use real-world settings have high ecological validity since participants behave more authentically. 

Limitations

Time-consuming .

Qualitative research results in large amounts of data which often need to be transcribed and analyzed manually.

Even when software is used, transcription can be inaccurate, and using software for analysis can result in many codes which need to be condensed into themes. 

Subjectivity 

The researcher has an integral role in collecting and interpreting qualitative data. Therefore, the conclusions reached are from their perspective and experience.

Consequently, interpretations of data from another researcher may vary greatly. 

Limited generalizability

The aim of qualitative research is to provide a detailed, contextualized understanding of an aspect of the human experience from a relatively small sample size.

Despite rigorous analysis procedures, conclusions drawn cannot be generalized to the wider population since data may be biased or unrepresentative.

Therefore, results are only applicable to a small group of the population. 

Extraneous variables

Qualitative research is often conducted in real-world settings. This may cause results to be unreliable since extraneous variables may affect the data, for example:

• Situational variables : different environmental conditions may influence participants’ behavior in a study. The random variation in factors (such as noise or lighting) may be difficult to control in real-world settings.
• Participant characteristics : this includes any characteristics that may influence how a participant answers/ behaves in a study. This may include a participant’s mood, gender, age, ethnicity, sexual identity, IQ, etc.
• Experimenter effect : experimenter effect refers to how a researcher’s unintentional influence can change the outcome of a study. This occurs when (i) their interactions with participants unintentionally change participants’ behaviors or (ii) due to errors in observation, interpretation, or analysis. 

What sample size should qualitative research be?

The sample size for qualitative studies has been recommended to include a minimum of 12 participants to reach data saturation (Braun, 2013).

Are surveys qualitative or quantitative?

Surveys can be used to gather information from a sample qualitatively or quantitatively. Qualitative surveys use open-ended questions to gather detailed information from a large sample using free text responses.

The use of open-ended questions allows for unrestricted responses where participants use their own words, enabling the collection of more in-depth information than closed-ended questions.

In contrast, quantitative surveys consist of closed-ended questions with multiple-choice answer options. Quantitative surveys are ideal to gather a statistical representation of a population.

What are the ethical considerations of qualitative research?

Before conducting a study, you must think about any risks that could occur and take steps to prevent them. Participant Protection : Researchers must protect participants from physical and mental harm. This means you must not embarrass, frighten, offend, or harm participants. Transparency : Researchers are obligated to clearly communicate how they will collect, store, analyze, use, and share the data. Confidentiality : You need to consider how to maintain the confidentiality and anonymity of participants’ data.

What is triangulation in qualitative research?

Triangulation refers to the use of several approaches in a study to comprehensively understand phenomena. This method helps to increase the validity and credibility of research findings. 

Types of triangulation include method triangulation (using multiple methods to gather data); investigator triangulation (multiple researchers for collecting/ analyzing data), theory triangulation (comparing several theoretical perspectives to explain a phenomenon), and data source triangulation (using data from various times, locations, and people; Carter et al., 2014).

Why is qualitative research important?

Qualitative research allows researchers to describe and explain the social world. The exploratory nature of qualitative research helps to generate hypotheses that can then be tested quantitatively.

In qualitative research, participants are able to express their thoughts, experiences, and feelings without constraint.

Additionally, researchers are able to follow up on participants’ answers in real-time, generating valuable discussion around a topic. This enables researchers to gain a nuanced understanding of phenomena which is difficult to attain using quantitative methods.

What is coding data in qualitative research?

Coding data is a qualitative data analysis strategy in which a section of text is assigned with a label that describes its content.

These labels may be words or phrases which represent important (and recurring) patterns in the data.

This process enables researchers to identify related content across the dataset. Codes can then be used to group similar types of data to generate themes.

What is the difference between qualitative and quantitative research?

Qualitative research involves the collection and analysis of non-numerical data in order to understand experiences and meanings from the participant’s perspective.

This can provide rich, in-depth insights on complicated phenomena. Qualitative data may be collected using interviews, focus groups, or observations.

In contrast, quantitative research involves the collection and analysis of numerical data to measure the frequency, magnitude, or relationships of variables. This can provide objective and reliable evidence that can be generalized to the wider population.

Quantitative data may be collected using closed-ended questionnaires or experiments.

What is trustworthiness in qualitative research?

Trustworthiness is a concept used to assess the quality and rigor of qualitative research. Four criteria are used to assess a study’s trustworthiness: credibility, transferability, dependability, and confirmability. 

Credibility refers to how accurately the results represent the reality and viewpoints of the participants. Transferability refers to whether the findings may be applied to another context, setting, or group.

Dependability is the extent to which the findings are consistent and reliable. Confirmability refers to the objectivity of findings (not influenced by the bias or assumptions of researchers).

What is data saturation in qualitative research?

Data saturation is a methodological principle used to guide the sample size of a qualitative research study.

Data saturation is proposed as a necessary methodological component in qualitative research (Saunders et al., 2018) as it is a vital criterion for discontinuing data collection and/or analysis. 

The intention of data saturation is to find “no new data, no new themes, no new coding, and ability to replicate the study” (Guest et al., 2006). Therefore, enough data has been gathered to make conclusions.

Why is sampling in qualitative research important?

In quantitative research, large sample sizes are used to provide statistically significant quantitative estimates.

This is because quantitative research aims to provide generalizable conclusions that represent populations.

However, the aim of sampling in qualitative research is to gather data that will help the researcher understand the depth, complexity, variation, or context of a phenomenon. The small sample sizes in qualitative studies support the depth of case-oriented analysis.

Boeije, H. (2014). Analysis in qualitative research. Sage.

Braun, V., & Clarke, V. (2006). Using thematic analysis in psychology. Qualitative research in psychology , 3 (2), 77-101. https://doi.org/10.1191/1478088706qp063oa

Brooks, J., McCluskey, S., Turley, E., & King, N. (2014). The utility of template analysis in qualitative psychology research. Qualitative Research in Psychology , 12 (2), 202–222. https://doi.org/10.1080/14780887.2014.955224

Busetto, L., Wick, W., & Gumbinger, C. (2020). How to use and assess qualitative research methods. Neurological research and practice , 2 (1), 14-14. https://doi.org/10.1186/s42466-020-00059-z 

Carter, N., Bryant-Lukosius, D., DiCenso, A., Blythe, J., & Neville, A. J. (2014). The use of triangulation in qualitative research. Oncology nursing forum , 41 (5), 545–547. https://doi.org/10.1188/14.ONF.545-547

Critical Appraisal Skills Programme. (2018). CASP Checklist: 10 questions to help you make sense of a Qualitative research. https://casp-uk.net/images/checklist/documents/CASP-Qualitative-Studies-Checklist/CASP-Qualitative-Checklist-2018_fillable_form.pdf Accessed: March 15 2023

Clarke, V., & Braun, V. (2013). Successful qualitative research: A practical guide for beginners. Successful Qualitative Research , 1-400.

Denny, E., & Weckesser, A. (2022). How to do qualitative research?: Qualitative research methods. BJOG : an international journal of obstetrics and gynaecology , 129 (7), 1166-1167. https://doi.org/10.1111/1471-0528.17150 

Glaser, B. G., & Strauss, A. L. (2017). The discovery of grounded theory. The Discovery of Grounded Theory , 1–18. https://doi.org/10.4324/9780203793206-1

Guest, G., Bunce, A., & Johnson, L. (2006). How many interviews are enough? An experiment with data saturation and variability. Field Methods, 18 (1), 59-82. doi:10.1177/1525822X05279903

Halpren, E. S. (1983). Auditing naturalistic inquiries: The development and application of a model (Unpublished doctoral dissertation). Indiana University, Bloomington.

Hammarberg, K., Kirkman, M., & de Lacey, S. (2016). Qualitative research methods: When to use them and how to judge them. Human Reproduction , 31 (3), 498–501. https://doi.org/10.1093/humrep/dev334

Koch, T. (1994). Establishing rigour in qualitative research: The decision trail. Journal of Advanced Nursing, 19, 976–986. doi:10.1111/ j.1365-2648.1994.tb01177.x

Lincoln, Y., & Guba, E. G. (1985). Naturalistic inquiry. Newbury Park, CA: Sage.

Mays, N., & Pope, C. (2000). Assessing quality in qualitative research. BMJ, 320(7226), 50–52.

Minichiello, V. (1990). In-Depth Interviewing: Researching People. Longman Cheshire.

Nowell, L. S., Norris, J. M., White, D. E., & Moules, N. J. (2017). Thematic Analysis: Striving to Meet the Trustworthiness Criteria. International Journal of Qualitative Methods, 16 (1). https://doi.org/10.1177/1609406917733847

Petty, N. J., Thomson, O. P., & Stew, G. (2012). Ready for a paradigm shift? part 2: Introducing qualitative research methodologies and methods. Manual Therapy , 17 (5), 378–384. https://doi.org/10.1016/j.math.2012.03.004

Punch, K. F. (2013). Introduction to social research: Quantitative and qualitative approaches. London: Sage

Reeves, S., Kuper, A., & Hodges, B. D. (2008). Qualitative research methodologies: Ethnography. BMJ , 337 (aug07 3). https://doi.org/10.1136/bmj.a1020

Russell, C. K., & Gregory, D. M. (2003). Evaluation of qualitative research studies. Evidence Based Nursing, 6 (2), 36–40.

Saunders, B., Sim, J., Kingstone, T., Baker, S., Waterfield, J., Bartlam, B., Burroughs, H., & Jinks, C. (2018). Saturation in qualitative research: exploring its conceptualization and operationalization. Quality & quantity , 52 (4), 1893–1907. https://doi.org/10.1007/s11135-017-0574-8

Scarduzio, J. A. (2017). Emic approach to qualitative research. The International Encyclopedia of Communication Research Methods, 1–2 . https://doi.org/10.1002/9781118901731.iecrm0082

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5 Characteristics of a Research Report

exist certain characteristics of a research report that distinguish it from other types of academic texts. In that sense, academic writing refers to a style of expression that exhibits some distinctive features.

Among them is the use of a formal tone, the preference for the employment of the third person and the precise choice of words.

On the other hand, a research report is a written document that describes an investigative work from beginning to end. The specific details in a report vary according to the type of inquiry.

In addition, specific conventions for writing in each of the scientific disciplines must be taken into account.

Main characteristics of a research report

Clarity of thought and language.

Clarity of thought and language are among the most essential characteristics of a research report. It is important to highlight that research is a thought process that begins even before choosing the topic of study.

The reasoning power of the researcher is the effective tool for the decisions that must be made throughout the process. This process demands a patient, deep and alert thinking.

In this way, clear thinking results in clear writing. As far as possible, sentences should be simple and important points should be highlighted in small paragraphs. This clarity will make the reader easily understand what the author of the report wants to say.

Conceptual clarity

Another characteristic of a research report is its conceptual clarity. The concepts in a study must be defined and explained. In general, the explanations of a dictionary are almost never adequate for research purposes.

Therefore, it is important to be very explicit, even with that terminology that seems to be very simple. It must be taken into account that the same term may have different definitions in different areas of knowledge.

Explicit statement of the research problem

The research report must establish the problem studied explicitly and unambiguously. In the case of Quantitative investigation , the problem statement must specify the variables and the population subject to study.

This approach can be made in declarative or question form. For its part, in qualitative research, the approach is much broader and indicates the general purpose of the study.

Organization and format

Research reports must observe certain standards of format and organization. The details of the format (type and size of source, margins, form of citing sources, presentation of the list of references, among others), are regulated by each institution.

On the other hand, other characteristics, such as the general organization, reflect the expectations of the scientific community. In this way, it is expected that the report contains a general summary, introduction (with the background and motivation of the study), materials and methods, results and the analysis of results.

Use of citations and list of references

It is very common that when conducting an investigation the intellectual property of another author is used. In research reports, an appointment should be suitably included when referring, summarizing, paraphrasing or quoting from another source. There are multiple formats for dating styles, and they vary according to the academic discipline.

In addition, the report must contain the list of references. These offer all the necessary information to locate the sources.

• University of Southern California. (2017, December 08). Organizing Your Social Sciences Research Paper: Academic Writing Style. Retrieved on December 29, 2017, from libguides.usc.edu .
• Locke, L. F.; Silverman, St. J. and Spirduso, W.W. (2004). Reading and Understanding Research. Thousand Oaks: SAGE.
• Cauvery, R.; Sudha, U. K.; Girija, M. and Meena kshi, R. (2003). Research Methodology. New Delhi: S. Chand Publishing.
• Profetto-McGrath, J.; Polit, D. F. and Beck, C. T. (2010). Canadian Essentials of Nursing Research. Philadelphia: Lippincott Williams & Wilkins.
• Ary, D.; Jacobs, L. C. and Sorensen, C. (2009). Introduction to Research in Education. Belmond: Cengage Learning.
• Westervelt, M. (s / f). Research Paper Organization and Content. Retrieved on December 29, 2017, from seas.upenn.edu.
• Penn State University. (2017, October 12). In-text Citation. Retrieved on December 29, 2017, from guides.libraries.psu.edu.
• The University of Tennessee. (s / f). Citing Sources and Avoiding Plagiarism. Retrieved on December 29, 2017, from guides.libraries.psu.edu.

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• Review Article
• Published: 06 October 2020

Characteristics of SARS-CoV-2 and COVID-19

• Ben Hu   ORCID: orcid.org/0000-0001-9194-3474 1   na1 ,
• Hua Guo   ORCID: orcid.org/0000-0003-4388-6465 1 , 2   na1 ,
• Peng Zhou   ORCID: orcid.org/0000-0001-9863-4201 1 &
• Zheng-Li Shi   ORCID: orcid.org/0000-0001-8089-163X 1  

Nature Reviews Microbiology volume  19 ,  pages 141–154 ( 2021 ) Cite this article

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An Author Correction to this article was published on 23 February 2022

This article has been updated

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and pathogenic coronavirus that emerged in late 2019 and has caused a pandemic of acute respiratory disease, named ‘coronavirus disease 2019’ (COVID-19), which threatens human health and public safety. In this Review, we describe the basic virology of SARS-CoV-2, including genomic characteristics and receptor use, highlighting its key difference from previously known coronaviruses. We summarize current knowledge of clinical, epidemiological and pathological features of COVID-19, as well as recent progress in animal models and antiviral treatment approaches for SARS-CoV-2 infection. We also discuss the potential wildlife hosts and zoonotic origin of this emerging virus in detail.

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Introduction

Coronaviruses are a diverse group of viruses infecting many different animals, and they can cause mild to severe respiratory infections in humans. In 2002 and 2012, respectively, two highly pathogenic coronaviruses with zoonotic origin, severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), emerged in humans and caused fatal respiratory illness, making emerging coronaviruses a new public health concern in the twenty-first century 1 . At the end of 2019, a novel coronavirus designated as SARS-CoV-2 emerged in the city of Wuhan, China, and caused an outbreak of unusual viral pneumonia. Being highly transmissible, this novel coronavirus disease, also known as coronavirus disease 2019 (COVID-19), has spread fast all over the world 2 , 3 . It has overwhelmingly surpassed SARS and MERS in terms of both the number of infected people and the spatial range of epidemic areas. The ongoing outbreak of COVID-19 has posed an extraordinary threat to global public health 4 , 5 . In this Review, we summarize the current understanding of the nature of SARS-CoV-2 and COVID-19. On the basis of recently published findings, this comprehensive Review covers the basic biology of SARS-CoV-2, including the genetic characteristics, the potential zoonotic origin and its receptor binding. Furthermore, we will discuss the clinical and epidemiological features, diagnosis of and countermeasures against COVID-19.

Emergence and spread

In late December 2019, several health facilities in Wuhan, in Hubei province in China, reported clusters of patients with pneumonia of unknown cause 6 . Similarly to patients with SARS and MERS, these patients showed symptoms of viral pneumonia, including fever, cough and chest discomfort, and in severe cases dyspnea and bilateral lung infiltration 6 , 7 . Among the first 27 documented hospitalized patients, most cases were epidemiologically linked to Huanan Seafood Wholesale Market, a wet market located in downtown Wuhan, which sells not only seafood but also live animals, including poultry and wildlife 4 , 8 . According to a retrospective study, the onset of the first known case dates back to 8 December 2019 (ref. 9 ). On 31 December, Wuhan Municipal Health Commission notified the public of a pneumonia outbreak of unidentified cause and informed the World Health Organization (WHO) 9 (Fig.  1 ).

The first recorded cases were reported in December 2019 in Wuhan, China. Over the course of the following 10 months, more than 30 million cases have been confirmed worldwide. COVID-19, coronavirus disease 2019; ICTV, International Committee on Taxonomy of Viruses; PHEIC, public health emergency of international concern; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2; WHO, World Health Organization.

By metagenomic RNA sequencing and virus isolation from bronchoalveolar lavage fluid samples from patients with severe pneumonia, independent teams of Chinese scientists identified that the causative agent of this emerging disease is a betacoronavirus that had never been seen before 6 , 10 , 11 . On 9 January 2020, the result of this etiological identification was publicly announced (Fig.  1 ). The first genome sequence of the novel coronavirus was published on the Virological website on 10 January, and more nearly complete genome sequences determined by different research institutes were then released via the GISAID database on 12 January 7 . Later, more patients with no history of exposure to Huanan Seafood Wholesale Market were identified. Several familial clusters of infection were reported, and nosocomial infection also occurred in health-care facilities. All these cases provided clear evidence for human-to-human transmission of the new virus 4 , 12 , 13 , 14 . As the outbreak coincided with the approach of the lunar New Year, travel between cities before the festival facilitated virus transmission in China. This novel coronavirus pneumonia soon spread to other cities in Hubei province and to other parts of China. Within 1 month, it had spread massively to all 34 provinces of China. The number of confirmed cases suddenly increased, with thousands of new cases diagnosed daily during late January 15 . On 30 January, the WHO declared the novel coronavirus outbreak a public health emergency of international concern 16 . On 11 February, the International Committee on Taxonomy of Viruses named the novel coronavirus ‘SARS-CoV-2’, and the WHO named the disease ‘COVID-19’ (ref. 17 ).

The outbreak of COVID-19 in China reached an epidemic peak in February. According to the National Health Commission of China, the total number of cases continued to rise sharply in early February at an average rate of more than 3,000 newly confirmed cases per day. To control COVID-19, China implemented unprecedentedly strict public health measures. The city of Wuhan was shut down on 23 January, and all travel and transportation connecting the city was blocked. In the following couple of weeks, all outdoor activities and gatherings were restricted, and public facilities were closed in most cities as well as in countryside 18 . Owing to these measures, the daily number of new cases in China started to decrease steadily 19 .

However, despite the declining trend in China, the international spread of COVID-19 accelerated from late February. Large clusters of infection have been reported from an increasing number of countries 18 . The high transmission efficiency of SARS-CoV-2 and the abundance of international travel enabled rapid worldwide spread of COVID-19. On 11 March 2020, the WHO officially characterized the global COVID-19 outbreak as a pandemic 20 . Since March, while COVID-19 in China has become effectively controlled, the case numbers in Europe, the USA and other regions have jumped sharply. According to the COVID-19 dashboard of the Center for System Science and Engineering at Johns Hopkins University, as of 11 August 2020, 216 countries and regions from all six continents had reported more than 20 million cases of COVID-19, and more than 733,000 patients had died 21 . High mortality occurred especially when health-care resources were overwhelmed. The USA is the country with the largest number of cases so far.

Although genetic evidence suggests that SARS-CoV-2 is a natural virus that likely originated in animals, there is no conclusion yet about when and where the virus first entered humans. As some of the first reported cases in Wuhan had no epidemiological link to the seafood market 22 , it has been suggested that the market may not be the initial source of human infection with SARS-CoV-2. One study from France detected SARS-CoV-2 by PCR in a stored sample from a patient who had pneumonia at the end of 2019, suggesting SARS-CoV-2 might have spread there much earlier than the generally known starting time of the outbreak in France 23 . However, this individual early report cannot give a solid answer to the origin of SARS-CoV-2 and contamination, and thus a false positive result cannot be excluded. To address this highly controversial issue, further retrospective investigations involving a larger number of banked samples from patients, animals and environments need to be conducted worldwide with well-validated assays.

Genomics, phylogeny and taxonomy

As a novel betacoronavirus, SARS-CoV-2 shares 79% genome sequence identity with SARS-CoV and 50% with MERS-CoV 24 . Its genome organization is shared with other betacoronaviruses. The six functional open reading frames (ORFs) are arranged in order from 5′ to 3′: replicase (ORF1a/ORF1b), spike (S), envelope (E), membrane (M) and nucleocapsid (N). In addition, seven putative ORFs encoding accessory proteins are interspersed between the structural genes 25 . Most of the proteins encoded by SARS-CoV-2 have a similar length to the corresponding proteins in SARS-CoV. Of the four structural genes, SARS-CoV-2 shares more than 90% amino acid identity with SARS-CoV except for the S gene, which diverges 11 , 24 . The replicase gene covers two thirds of the 5′ genome, and encodes a large polyprotein (pp1ab),which is proteolytically cleaved into 16 non-structural proteins that are involved in transcription and virus replication. Most of these SARS-CoV-2 non-structural proteins have greater than 85% amino acid sequence identity with SARS-CoV 25 .

The phylogenetic analysis for the whole genome shows that SARS-CoV-2 is clustered with SARS-CoV and SARS-related coronaviruses (SARSr-CoVs) found in bats, placing it in the subgenus Sarbecovirus of the genus Betacoronavirus. Within this clade, SARS-CoV-2 is grouped in a distinct lineage together with four horseshoe bat coronavirus isolates (RaTG13, RmYN02, ZC45 and ZXC21) as well as novel coronaviruses recently identified in pangolins, which group parallel to SARS-CoV and other SARSr-CoVs (Fig.  2 ). Using sequences of five conserved replicative domains in pp1ab (3C-like protease (3CLpro), nidovirus RNA-dependent RNA polymerase (RdRp)-associated nucleotidyltransferase (NiRAN), RdRp, zinc-binding domain (ZBD) and HEL1), the Coronaviridae Study Group of the International Committee on Taxonomy of Viruses estimated the pairwise patristic distances between SARS-CoV-2 and known coronaviruses, and assigned SARS-CoV-2 to the existing species SARSr-CoV 17 . Although phylogenetically related, SARS-CoV-2 is distinct from all other coronaviruses from bats and pangolins in this species.

The construction was performed by the neighbour joining method with use of the program MEGA6 with bootstrap values being calculated from 1,000 trees. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clusters with closely related viruses in bats and pangolins and together with SARS-CoV and bat SARS-related coronaviruses (SARSr-CoVs) forms the sarbecoviruses. The sequences were downloaded from the GISAID database and GenBank. MERS-CoV, Middle East respiratory syndrome coronavirus.

The SARS-CoV-2 S protein has a full size of 1,273 amino acids, longer than that of SARS-CoV (1,255 amino acids) and known bat SARSr-CoVs (1,245–1,269 amino acids). It is distinct from the S proteins of most members in the subgenus Sarbecovirus, sharing amino acid sequence similarities of 76.7–77.0% with SARS-CoVs from civets and humans, 75–97.7% with bat coronaviruses in the same subgenus and 90.7–92.6% with pangolin coronaviruses 11 . In the receptor-binding domain (RBD) of S protein, the amino acid similarity between SARS-CoV-2 and SARS-CoV is only 73%. Another specific genomic feature of SARS-CoV-2 is the insertion of four amino acid residues (PRRA) at the junction of subunits S1 and S2 of the S protein 26 (Fig.  3a ). This insertion generates a polybasic cleavage site (RRAR), which enables effective cleavage by furin and other proteases 27 . Such an S1–S2 cleavage site is not observed in all related viruses belonging to the subgenus Sarbecovirus, except for a similar three amino acid insertion (PAA) in RmYN02, a bat-derived coronavirus newly reported from Rhinolophus malayanus in China 28 (Fig.  3a ). Although the insertion in RmYN02 does not functionally represent a polybasic cleavage site, it provides support for the notion that this characteristic, initially considered unique to SARS-CoV-2, has been acquired naturally 28 . A structural study suggested that the furin-cleavage site can reduce the stability of SARS-CoV-2 S protein and facilitate the conformational adaption that is required for the binding of the RBD to its receptor 29 . Whether the higher transmissibility of SARS-CoV-2 compared with SARS-CoV is a gain of function associated with acquisition of the furin-like cleavage site is yet to be demonstrated 26 .

a | Schematic diagram of the spike (S) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) and SARS-CoV-2. The residue numbers of each region correspond to their positions in the S proteins of SARS-CoV and SARS-CoV-2. The dark blue blocks represent insertions in the S protein. The insertions at amino acids 675–691 of the SARS-CoV-2 S protein are shown in an enlargement at the bottom right and aligned with those of other coronaviruses in the same region. b | Alignment of the receptor-binding domain (RBD) in SARS-CoV-2, SARS-CoV BJ01, RaTG13, pangolin coronavirus reported from Guangdong, China (GD pangolin), pangolin coronavirus reported from Guangxi, China (GX pangolin) and bat SARS-related coronavirus (SARSr-CoV) WIV1. The receptor-binding motif (RBM) is shown in purple, and the five key residues that contact angiotensin-converting enzyme 2 (ACE2) directly are highlighted in green. c | Five critical residues in the RBD of SARS-CoV-2 and other viruses. d | Comparison of the structure of SARS-CoV-2 and SARS-CoV RBD complexed with human ACE2 (hACE2); SARS-CoV-2 RBM in purple, SARS-CoV RBM in yellow and hACE2 in green). Five critical residues that are involved in the RBM–ACE2 binding are shown. The Protein Data Bank codes are 2AJF for SARS-CoV RBD–hACE2 and 6VW1 for SARS-CoV-2 RBD–hACE2. The GenBank entries are AY278488 for SARS-CoV BJ01, MN996532 for the bat SARSr-CoV RaTG13, MT121216 and MT072864 for the GD pangolin and GX pangolin coronaviruses, respectively, and KF367457 for the bat SARSr-CoV WIV1. CP, cytoplasmic domain; FP, fusion peptide; HR1, heptad repeat 1; HR2, heptad repeat 2; NTD, N-terminal domain; SP, signal peptide; TM, transmembrane domain. Parts a and b adapted from ref. 26 , Springer Nature Limited.

An additional distinction is the accessory gene orf8 of SARS-CoV-2, which encodes a novel protein showing only 40% amino acid identity to ORF8 of SARS-CoV. Unlike in SARS-CoV, this new ORF8 protein does not contain a motif that triggers intracellular stress pathways 25 . Notably, a SARS-CoV-2 variant with a 382-nucleotide deletion covering the whole of ORF8 has been discovered in a number of patients in Singapore, which resembles the 29- or 415-nucleotide deletions in the ORF8 region observed in human SARS-CoV variants from the late phase of the 2002–2003 outbreak 30 . Such ORF8 deletion may be indicative of human adaptation after cross-species transmission from an animal host.

To assess the genetic variation of different SARS-CoV-2 strains, the 2019 Novel Coronavirus Resource of China National Center for Bioinformation aligned 77,801 genome sequences of SARS-CoV-2 detected globally and identified a total of 15,018 mutations, including 14,824 single-nucleotide polymorphisms ( BIGD ) 31 . In the S protein, four amino acid alterations, V483A, L455I, F456V and G476S, are located near the binding interface in the RBD, but their effects on binding to the host receptor are unknown. The alteration D614G in the S1 subunit was found far more frequently than other S variant sites, and it is the marker of a major subclade of SARS-CoV-2 (clade G). Since March 2020, SARS-CoV-2 variants with G614 in the S protein have replaced the original D614 variants and become the dominant form circulating globally. Compared with the D614 variant, higher viral loads were found in patients infected with the G614 variant, but clinical data suggested no significant link between the D614G alteration and disease severity 32 . Pseudotyped viruses carrying the S protein with G614 generated higher infectious titres than viruses carrying the S protein with D614, suggesting the alteration may have increased the infectivity of SARS-CoV-2 (ref. 32 ). However, the results of in vitro experiments based on pseudovirus models may not exactly reflect natural infection. This preliminary finding should be validated by more studies using wild-type SARS-CoV-2 variants to infect different target cells and animal models. Whether this amino acid change enhanced virus transmissibility is also to be determined. Another marker mutation for SARS-CoV-2 evolution is the single-nucleotide polymorphism at nucleotide position 28,144, which results in amino acid substitution of Ser for Lys at residue 84 of the ORF8 protein. Those variants with this mutation make up a single subclade labelled as ‘clade S’ 33 , 34 . Currently, however, the available sequence data are not sufficient to interpret the early global transmission history of the virus, and travel patterns, founder effects and public health measures also strongly influence the spread of particular lineages, irrespective of potential biological differences between different virus variants.

Animal host and spillover

Bats are important natural hosts of alphacoronaviruses and betacoronaviruses. The closest relative to SARS-CoV-2 known to date is a bat coronavirus detected in Rhinolophus affinis from Yunnan province, China, named ‘RaTG13’, whose full-length genome sequence is 96.2% identical to that of SARS-CoV-2 (ref. 11 ). This bat virus shares more than 90% sequence identity with SARS-CoV-2 in all ORFs throughout the genome, including the highly variable S and ORF8 (ref. 11 ). Phylogenetic analysis confirms that SARS-CoV-2 closely clusters with RaTG13 (Fig.  2 ). The high genetic similarity between SARS-CoV-2 and RaTG13 supports the hypothesis that SARS-CoV-2 likely originated from bats 35 . Another related coronavirus has been reported more recently in a Rhinolophus malayanus bat sampled in Yunnan. This novel bat virus, denoted ‘RmYN02’, is 93.3% identical to SARS-CoV-2 across the genome. In the long 1ab gene, it exhibits 97.2% identity to SARS-CoV-2, which is even higher than for RaTG13 (ref. 28 ). In addition to RaTG13 and RmYN02, phylogenetic analysis shows that bat coronaviruses ZC45 and ZXC21 previously detected in Rhinolophus pusillus bats from eastern China also fall into the SARS-CoV-2 lineage of the subgenus Sarbecovirus 36 (Fig.  2 ). The discovery of diverse bat coronaviruses closely related to SARS-CoV-2 suggests that bats are possible reservoirs of SARS-CoV-2 (ref. 37 ). Nevertheless, on the basis of current findings, the divergence between SARS-CoV-2 and related bat coronaviruses likely represents more than 20 years of sequence evolution, suggesting that these bat coronaviruses can be regarded only as the likely evolutionary precursor of SARS-CoV-2 but not as the direct progenitor of SARS-CoV-2 (ref. 38 ).

Beyond bats, pangolins are another wildlife host probably linked with SARS-CoV-2. Multiple SARS-CoV-2-related viruses have been identified in tissues of Malayan pangolins smuggled from Southeast Asia into southern China from 2017 to 2019. These viruses from pangolins independently seized by Guangxi and Guangdong provincial customs belong to two distinct sublineages 39 , 40 , 41 . The Guangdong strains, which were isolated or sequenced by different research groups from smuggled pangolins, have 99.8% sequence identity with each other 41 . They are very closely related to SARS-CoV-2, exhibiting 92.4% sequence similarity. Notably, the RBD of Guangdong pangolin coronaviruses is highly similar to that of SARS-CoV-2. The receptor-binding motif (RBM; which is part of the RBD) of these viruses has only one amino acid variation from SARS-CoV-2, and it is identical to that of SARS-CoV-2 in all five critical residues for receptor binding 40 (Fig.  3b ). In comparison with the Guangdong strains, pangolin coronaviruses reported from Guangxi are less similar to SARS-CoV-2, with 85.5% genome sequence identity 39 . The repeated occurrence of SARS-CoV-2-related coronavirus infections in pangolins from different smuggling events suggests that these animals are possible hosts of the viruses. However, unlike bats, which carry coronaviruses healthily, the infected pangolins showed clinical signs and histopathological changes, including interstitial pneumonia and inflammatory cell infiltration in diverse organs 40 . These abnormalities suggest that pangolins are unlikely to be the reservoir of these coronaviruses but more likely acquired the viruses after spillover from the natural hosts.

An intermediate host usually plays an important role in the outbreak of bat-derived emerging coronaviruses; for example, palm civets for SARS-CoV and dromedary camels for MERS-CoV. The virus strains carried by these two intermediate hosts were almost genetically identical to the corresponding viruses in humans (more than 99% genome sequence identity) 1 . Despise an RBD that is virtually identical to that of SARS-CoV-2, the pangolin coronaviruses known to date have no more than 92% genome identity with SARS-CoV-2 (ref. 42 ). The available data are insufficient to interpret pangolins as the intermediate host of SARS-CoV-2. So far, no evidence has shown that pangolins were directly involved in the emergence of SARS-CoV-2.

Currently, our knowledge on the animal origin of SARS-CoV-2 remains incomplete to a large part. The reservoir hosts of the virus have not been clearly proven. It is unknown whether SARS-CoV-2 was transmitted to humans through an intermediate host and which animals may act as its intermediate host. Detection of RaTG13, RmYN02 and pangolin coronaviruses implies that diverse coronaviruses similar to SARS-CoV-2 are circulating in wildlife. In addition, as previous studies showed recombination as the potential origin of some sarbecoviruses such as SARS-CoV, it cannot be excluded that viral RNA recombination among different related coronaviruses was involved in the evolution of SARS-CoV-2. Extensive surveillance of SARS-CoV-2-related viruses in China, Southeast Asia and other regions targeting bats, wild and captured pangolins and other wildlife species will help us to better understand the zoonotic origin of SARS-CoV-2.

Besides wildlife, researchers investigated the susceptibility of domesticated and laboratory animals to SARS-CoV-2 infection. The study demonstrated experimentally that SARS-CoV-2 replicates efficiently in cats and in the upper respiratory tract of ferrets, whereas dogs, pigs, chickens and ducks were not susceptible to SARS-CoV-2 (ref. 43 ). The susceptibility of minks was documented by a report from the Netherlands on an outbreak of SARS-CoV-2 infection in farmed minks. Although the symptoms in most infected minks were mild, some developed severe respiratory distress and died of interstitial pneumonia 44 . Both virological and serological testing found evidence for natural SARS-CoV-2 infection in two dogs from households with human cases of COVID-19 in Hong Kong, but the dogs appeared asymptomatic 45 . Another serological study detected SARS-CoV-2 neutralizing antibodies in cat serum samples collected in Wuhan after the COVID-19 outbreak, providing evidence for SARS-CoV-2 infection in cat populations in Wuhan, although the potential of SARS-CoV-2 transmission from cats to humans is currently uncertain 46 .

Receptor use and pathogenesis

SARS-CoV-2 uses the same receptor as SARS-CoV, angiotensin-converting enzyme 2 (ACE2) 11 , 47 . Besides human ACE2 (hACE2), SARS-CoV-2 also recognizes ACE2 from pig, ferret, rhesus monkey, civet, cat, pangolin, rabbit and dog 11 , 43 , 48 , 49 . The broad receptor usage of SARS-CoV-2 implies that it may have a wide host range, and the varied efficiency of ACE2 usage in different animals may indicate their different susceptibilities to SARS-CoV-2 infection. The S1 subunit of a coronavirus is further divided into two functional domains, an N-terminal domain and a C-terminal domain. Structural and biochemical analyses identified a 211 amino acid region (amino acids 319–529) at the S1 C-terminal domain of SARS-CoV-2 as the RBD, which has a key role in virus entry and is the target of neutralizing antibodies 50 , 51 (Fig.  3a ). The RBM mediates contact with the ACE2 receptor (amino acids 437–507 of SARS-CoV-2 S protein), and this region in SARS-CoV-2 differs from that in SARS-CoV in the five residues critical for ACE2 binding, namely Y455L, L486F, N493Q, D494S and T501N 52 (Fig.  3b , c ). Owing to these residue changes, interaction of SARS-CoV-2 with its receptor stabilizes the two virus-binding hotspots on the surface of hACE2 (ref. 50 ) (Fig.  3d ). Moreover, a four-residue motif in the RBM of SARS-CoV-2 (amino acids 482–485: G-V-E-G) results in a more compact conformation of its hACE2-binding ridge than in SARS-CoV and enables better contact with the N-terminal helix of hACE2 (ref. 50 ). Biochemical data confirmed that the structural features of the SARS-CoV-2 RBD has strengthened its hACE2 binding affinity compared with that of SARS-CoV 50 , 52 , 53 .

Similarly to other coronaviruses, SARS-CoV-2 needs proteolytic processing of the S protein to activate the endocytic route. It has been shown that host proteases participate in the cleavage of the S protein and activate the entry of SARS-CoV-2, including transmembrane protease serine protease 2 (TMPRSS2), cathepsin L and furin 47 , 54 , 55 . Single-cell RNA sequencing data showed that TMPRSS2 is highly expressed in several tissues and body sites and is co-expressed with ACE2 in nasal epithelial cells, lungs and bronchial branches, which explains some of the tissue tropism of SARS-CoV-2 (refs 56 , 57 ). SARS-CoV-2 pseudovirus entry assays revealed that TMPRSS2 and cathepsin L have cumulative effects with furin on activating virus entry 55 . Analysis of the cryo-electron microscopy structure of SARS-CoV-2 S protein revealed that its RBD is mostly in the lying-down state, whereas the SARS-CoV S protein assumes equally standing-up and lying-down conformational states 50 , 51 , 58 , 59 . A lying-down conformation of the SARS-CoV-2 S protein may not be in favour of receptor binding but is helpful for immune evasion 55 .

The pathogenesis of SARS-CoV-2 infection in humans manifests itself as mild symptoms to severe respiratory failure. On binding to epithelial cells in the respiratory tract, SARS-CoV-2 starts replicating and migrating down to the airways and enters alveolar epithelial cells in the lungs. The rapid replication of SARS-CoV-2 in the lungs may trigger a strong immune response. Cytokine storm syndrome causes acute respiratory distress syndrome and respiratory failure, which is considered the main cause of death in patients with COVID-19 (refs 60 , 61 ). Patients of older age (>60 years) and with serious pre-existing diseases have a greater risk of developing acute respiratory distress syndrome and death 62 , 63 , 64 (Fig.  4 ). Multiple organ failure has also been reported in some COVID-19 cases 9 , 13 , 65 .

Typical symptoms of coronavirus disease 2019 (COVID-19) are fever, dry cough and fatigue and in severer cases dyspnea. Many infections, in particular in children and young adults, are asymptomatic, whereas older people and/or people with co-morbidities are at higher risk of severe disease, respiratory failure and death. The incubation period is ~5 days, severe disease usually develops ~8 days after symptom onset and critical disease and death occur at ~16 days. ARDS, acute respiratory distress syndrome; ICU, intensive care unit.

Histopathological changes in patients with COVID-19 occur mainly in the lungs. Histopathology analyses showed bilateral diffused alveolar damage, hyaline membrane formation, desquamation of pneumocytes and fibrin deposits in lungs of patients with severe COVID-19. Exudative inflammation was also shown in some cases. Immunohistochemistry assays detected SARS-CoV-2 antigen in the upper airway, bronchiolar epithelium and submucosal gland epithelium, as well as in type I and type II pneumocytes, alveolar macrophages and hyaline membranes in the lungs 13 , 60 , 66 , 67 .

Animal models used for studying SARS-CoV-2 infection pathogenesis include non-human primates (rhesus macaques, cynomolgus monkeys, marmosets and African green monkeys), mice (wild-type mice (with mouse-adapted virus) and human ACE2 -transgenic or human ACE2 -knock-in mice), ferrets and golden hamsters 43 , 48 , 68 , 69 , 70 , 71 , 72 , 73 , 74 . In non-human primate animal models, most species display clinical features similar to those of patients with COVID-19, including virus shedding, virus replication and host responses to SARS-CoV-2 infection 69 , 72 , 73 . For example, in the rhesus macaque model, high viral loads were detected in the upper and lower respiratory tracts. Acute viral interstitial pneumonia and humoral and cellular immune responses were observed 48 , 75 . Moreover, prolonged virus shedding peaked early in the course of infection in asymptomatic macaques 69 , and old monkeys showed severer interstitial pneumonia than young monkeys 76 , which is similar to what is seen in patients with COVID-19. In human ACE2 -transgenic mice infected with SARS-CoV-2, typical interstitial pneumonia was present, and viral antigens were observed mainly in the bronchial epithelial cells, macrophages and alveolar epithelia. Some human ACE2 -transgenic mice even died after infection 70 , 71 . In wide-type mice, a SARS-CoV-2 mouse-adapted strain with the N501Y alteration in the RBD of the S protein was generated at passage 6. Interstitial pneumonia and inflammatory responses were found in both young and aged mice after infection with the mouse-adapted strain 74 . Golden hamsters also showed typical symptoms after being infected with SARS-CoV-2 (ref. 77 ). In other animal models, including cats and ferrets, SARS-CoV-2 could efficiently replicate in the upper respiratory tract but did not induce severe clinical symptoms 43 , 78 . As transmission by direct contact and air was observed in infected ferrets and hamsters, these animals could be used to model different transmission modes of COVID-19 (refs 77 , 78 , 79 ). Animal models offer important information for understanding the pathogenesis of SARS-CoV-2 infection and the transmission dynamics of SARS-CoV-2, and are important to evaluate the efficacy of antiviral therapeutics and vaccines.

Clinical and epidemiological features

It appears that all ages of the population are susceptible to SARS-CoV-2 infection, and the median age of infection is around 50 years 9 , 13 , 60 , 80 , 81 . However, clinical manifestations differ with age. In general, older men (>60 years old) with co-morbidities are more likely to develop severe respiratory disease that requires hospitalization or even die, whereas most young people and children have only mild diseases (non-pneumonia or mild pneumonia) or are asymptomatic 9 , 81 , 82 . Notably, the risk of disease was not higher for pregnant women. However, evidence of transplacental transmission of SARS-CoV-2 from an infected mother to a neonate was reported, although it was an isolated case 83 , 84 . On infection, the most common symptoms are fever, fatigue and dry cough 13 , 60 , 80 , 81 . Less common symptoms include sputum production, headache, haemoptysis, diarrhoea, anorexia, sore throat, chest pain, chills and nausea and vomiting in studies of patients in China 13 , 60 , 80 , 81 . Self-reported olfactory and taste disorders were also reported by patients in Italy 85 . Most people showed signs of diseases after an incubation period of 1–14 days (most commonly around 5 days), and dyspnoea and pneumonia developed within a median time of 8 days from illness onset 9 .

In a report of 72,314 cases in China, 81% of the cases were classified as mild, 14% were severe cases that required ventilation in an intensive care unit (ICU) and a 5% were critical (that is, the patients had respiratory failure, septic shock and/or multiple organ dysfunction or failure) 9 , 86 . On admission, ground-glass opacity was the most common radiologic finding on chest computed tomography (CT) 13 , 60 , 80 , 81 . Most patients also developed marked lymphopenia, similar to what was observed in patients with SARS and MERS, and non-survivors developed severer lymphopenia over time 13 , 60 , 80 , 81 . Compared with non-ICU patients, ICU patients had higher levels of plasma cytokines, which suggests an immunopathological process caused by a cytokine storm 60 , 86 , 87 . In this cohort of patient, around 2.3% people died within a median time of 16 days from disease onset 9 , 86 . Men older than 68 years had a higher risk of respiratory failure, acute cardiac injury and heart failure that led to death, regardless of a history of cardiovascular disease 86 (Fig.  4 ). Most patients recovered enough to be released from hospital in 2 weeks 9 , 80 (Fig.  4 ).

Early transmission of SARS-CoV-2 in Wuhan in December 2019 was initially linked to the Huanan Seafood Wholesale Market, and it was suggested as the source of the outbreak 9 , 22 , 60 . However, community transmission might have happened before that 88 . Later, ongoing human-to-human transmission propagated the outbreak 9 . It is generally accepted that SARS-CoV-2 is more transmissible than SARS-CoV and MERS-CoV; however, determination of an accurate reproduction number (R0) for COVID-19 is not possible yet, as many asymptomatic infections cannot be accurately accounted for at this stage 89 . An estimated R0 of 2.5 (ranging from 1.8 to 3.6) has been proposed for SARS-CoV-2 recently, compared with 2.0–3.0 for SARS-CoV 90 . Notably, most of the SARS-CoV-2 human-to-human transmission early in China occurred in family clusters, and in other countries large outbreaks also happened in other settings, such as migrant worker communities, slaughterhouses and meat packing plants, indicating the necessity of isolating infected people 9 , 12 , 91 , 92 , 93 . Nosocomial transmission was not the main source of transmission in China because of the implementation of infection control measures in clinical settings 9 . By contrast, a high risk of nosocomial transmission was reported in some other areas. For example, a cohort study in London revealed 44% of the frontline health-care workers from a hospital were infected with SARS-CoV-2 (ref. 94 ).

The high transmissibility of SARS-CoV-2 may be attributed to the unique virological features of SARS-CoV-2. Transmission of SARS-CoV occurred mainly after illness onset and peaked following disease severity 95 . However, the SARS-CoV-2 viral load in upper respiratory tract samples was already highest during the first week of symptoms, and thus the risk of pharyngeal virus shedding was very high at the beginning of infection 96 , 97 . It was postulated that undocumented infections might account for 79% of documented cases owing to the high transmissibility of the virus during mild disease or the asymptomatic period 89 . A patient with COVID-19 spreads viruses in liquid droplets during speech. However, smaller and much more numerous particles known as aerosol particles can also be visualized, which could linger in the air for a long time and then penetrate deep into the lungs when inhaled by someone else 98 , 99 , 100 . Airborne transmission was also observed in the ferret experiments mentioned above. SARS-CoV-2-infected ferrets shed viruses in nasal washes, saliva, urine and faeces for up to 8 days after infection, and a few naive ferrets with only indirect contact were positive for viral RNA, suggesting airborne transmission 78 . In addition, transmission of the virus through the ocular surface and prolonged presence of SARS-CoV-2 viral RNA in faecal samples were also documented 101 , 102 . Coronaviruses can persist on inanimate surfaces for days, which could also be the case for SARS-CoV-2 and could pose a prolonged risk of infection 103 . These findings explain the rapid geographic spread of COVID-19, and public health interventions to reduce transmission will provide benefit to mitigate the epidemic, as has proved successful in China and several other countries, such as South Korea 89 , 104 , 105 .

Early diagnosis is crucial for controlling the spread of COVID-19. Molecular detection of SARS-CoV-2 nucleic acid is the gold standard. Many viral nucleic acid detection kits targeting ORF1b (including RdRp), N, E or S genes are commercially available 11 , 106 , 107 , 108 , 109 . The detection time ranges from several minutes to hours depending on the technology 106 , 107 , 109 , 110 , 111 . The molecular detection can be affected by many factors. Although SARS-CoV-2 has been detected from a variety of respiratory sources, including throat swabs, posterior oropharyngeal saliva, nasopharyngeal swabs, sputum and bronchial fluid, the viral load is higher in lower respiratory tract samples 11 , 96 , 112 , 113 , 114 , 115 . In addition, viral nucleic acid was also found in samples from the intestinal tract or blood even when respiratory samples were negative 116 . Lastly, viral load may already drop from its peak level on disease onset 96 , 97 . Accordingly, false negatives can be common when oral swabs and used, and so multiple detection methods should be adopted to confirm a COVID-19 diagnosis 117 , 118 . Other detection methods were therefore used to overcome this problem. Chest CT was used to quickly identify a patient when the capacity of molecular detection was overloaded in Wuhan. Patients with COVID-19 showed typical features on initial CT, including bilateral multilobar ground-glass opacities with a peripheral or posterior distribution 118 , 119 . Thus, it has been suggested that CT scanning combined with repeated swab tests should be used for individuals with high clinical suspicion of COVID-19 but who test negative in initial nucleic acid screening 118 . Finally, SARS-CoV-2 serological tests detecting antibodies to N or S protein could complement molecular diagnosis, particularly in late phases after disease onset or for retrospective studies 116 , 120 , 121 . However, the extent and duration of immune responses are still unclear, and available serological tests differ in their sensitivity and specificity, all of which need to be taken into account when one is deciding on serological tests and interpreting their results or potentially in the future test for T cell responses.

Therapeutics

To date, there are no generally proven effective therapies for COVID-19 or antivirals against SARS-CoV-2, although some treatments have shown some benefits in certain subpopulations of patients or for certain end points (see later). Researchers and manufacturers are conducting large-scale clinical trials to evaluate various therapies for COVID-19. As of 2 October 2020, there were about 405 therapeutic drugs in development for COVID-19, and nearly 318 in human clinical trials ( COVID-19 vaccine and therapeutics tracker ). In the following sections, we summarize potential therapeutics against SARS-CoV-2 on the basis of published clinical data and experience.

Inhibition of virus entry

SARS-CoV-2 uses ACE2 as the receptor and human proteases as entry activators; subsequently it fuses the viral membrane with the cell membrane and achieves invasion. Thus, drugs that interfere with entry may be a potential treatment for COVID-19. Umifenovir (Arbidol) is a drug approved in Russia and China for the treatment of influenza and other respiratory viral infections. It can target the interaction between the S protein and ACE2 and inhibit membrane fusion (Fig.  5 ). In vitro experiments showed that it has activity against SARS-CoV-2, and current clinical data revealed it may be more effective than lopinavir and ritonavir in treating COVID-19 (refs 122 , 123 ). However, other clinical studies showed umifenovir might not improve the prognosis of or accelerate SARS-CoV-2 clearance in patients with mild to moderate COVID-19 (refs 124 , 125 ). Yet some ongoing clinical trials are evaluating its efficacy for COVID-19 treatment. Camostat mesylate is approved in Japan for the treatment of pancreatitis and postoperative reflux oesophagitis. Previous studies showed that it can prevent SARS-CoV from entering cells by blocking TMPRSS2 activity and protect mice from lethal infection with SARS-CoV in a pathogenic mouse model (wild-type mice infected with a mouse-adapted SARS-CoV strain) 126 , 127 . Recently, a study revealed that camostat mesylate blocks the entry of SARS-CoV-2 into human lung cells 47 . Thus, it can be a potential antiviral drug against SARS-CoV-2 infection, although so far there are not sufficient clinical data to support its efficacy.

Potential antivirals target the different steps of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication, ranging from receptor binding, entry and fusion to replication. Furthermore, immunoglobulin-based and immunomodulatory drugs are potential therapeutics as well. Note that robust data on clinical efficacy are lacking for most of these treatments so far. 3CLpro, 3C-like protease; ACE2, angiotensin-converting enzyme 2; CR3022, a SARS-CoV-specific human monoclonal antibody; E, envelope protein; EK1C4, lipopeptide derived from EK1 which is a pan-coronavirus fusion inhibitor targeting the HR1 domain of the spike protein; ER, endoplasmic reticulum; gRNA, genomic RNA; HR2P, heptad repeat 2-derived peptides of SARS-CoV-2 spike protein; IL-6, interleukin-6; ISG, interferon-stimulated gene; M, membrane protein; RdRp, RNA-dependent RNA polymerases; sgRNA, subgenomic RNA; S, spike protein; TMPRSS2, transmembrane protease serine protease 2.

Chloroquine and hydroxychloroquine are other potential but controversial drugs that interfere with the entry of SARS-CoV-2. They have been used in the prevention and treatment of malaria and autoimmune diseases, including systemic lupus erythematosus and rheumatoid arthritis. They can inhibit the glycosylation of cellular receptors and interfere with virus–host receptor binding, as well as increase the endosomal pH and inhibit membrane fusion. Currently, no scientific consensus has been reached for their efficacy in the treatment of COVID-19. Some studies showed they can inhibit SARS-CoV-2 infection in vitro, but the clinical data are insufficient 128 , 129 . Two clinical studies indicated no association with death rates in patients receiving chloroquine or hydroxychloroquine compared with those not receiving the drug and even suggest it may increase the risk of dying as a higher risk of cardiac arrest was found in the treated patients 130 , 131 . On 15 June 2020, owing to the side effects observed in clinical trials, the US Food and Drug Administration (FDA) revoked the emergency use authorization for chloroquine and hydroxychloroquine for the treatment of COVID-19. Another potential therapeutic strategy is to block binding of the S protein to ACE2 through soluble recombinant hACE2, specific monoclonal antibodies or fusion inhibitors that target the SARS-CoV-2 S protein 132 , 133 , 134 (Fig.  5 ). The safety and efficacy of these strategies need to be assessed in future clinical trials.

Inhibition of virus replication

Replication inhibitors include remdesivir (GS-5734), favilavir (T-705), ribavirin, lopinavir and ritonavir. Except for lopinavir and ritonavir, which inhibit 3CLpro, the other three all target RdRp 128 , 135 (Fig.  5 ). Remdesivir has shown activity against SARS-CoV-2 in vitro and in vivo 128 , 136 . A clinical study revealed a lower need for oxygen support in patients with COVID-19 (ref. 137 ). Preliminary results of the Adaptive COVID-19 Treatment Trial (ACTT) clinical trial by the National Institute of Allergy and Infectious Diseases (NIAID) reported that remdesivir can shorten the recovery time in hospitalized adults with COVID-19 by a couple days compared with placebo, but the difference in mortality was not statistically significant 138 . The FDA has issued an emergency use authorization for remdesivir for the treatment of hospitalized patients with severe COVID-19. It is also the first approved option by the European Union for treatment of adults and adolescents with pneumonia requiring supplemental oxygen. Several international phase III clinical trials are continuing to evaluate the safety and efficacy of remdesivir for the treatment of COVID-19.

Favilavir (T-705), which is an antiviral drug developed in Japan to treat influenza, has been approved in China, Russia and India for the treatment of COVID-19. A clinical study in China showed that favilavir significantly reduced the signs of improved disease signs on chest imaging and shortened the time to viral clearance 139 . A preliminary report in Japan showed rates of clinical improvement of 73.8% and 87.8% from the start of favilavir therapy in patients with mild COVID-19 at 7 and 14 days, respectively, and 40.1% and 60.3% in patients with severe COVID-19 at 7 and 14 days, respectively 140 . However, this study did not include a control arm, and most of the trials of favilavir were based on a small sample size. For more reliable assessment of the effectiveness of favilavir for treating COVID-19, large-scale randomized controlled trials should be conducted.

Lopinavir and ritonavir were reported to have in vitro inhibitory activity against SARS-CoV and MERS-CoV 141 , 142 . Alone, the combination of lopinavir and ritonavir had little therapeutic benefit in patients with COVID-19, but appeared more effective when used in combination with other drugs, including ribavirin and interferon beta-1b 143 , 144 . The Randomized Evaluation of COVID-19 Therapy (RECOVERY) trial, a national clinical trial programme in the UK, has stopped treatment with lopinavir and ritonavir as no significant beneficial effect was observed in a randomized trial established in March 2020 with a total of 1,596 patients 145 . Nevertheless, other clinical trials in different phases are still ongoing elsewhere.

Immunomodulatory agents

SARS-CoV-2 triggers a strong immune response which may cause cytokine storm syndrome 60 , 61 . Thus, immunomodulatory agents that inhibit the excessive inflammatory response may be a potential adjunctive therapy for COVID-19. Dexamethasone is a corticosteroid often used in a wide range of conditions to relieve inflammation through its anti-inflammatory and immunosuppressant effects. Recently, the RECOVERY trial found dexamethasone reduced mortality by about one third in hospitalized patients with COVID-19 who received invasive mechanical ventilation and by one fifth in patients receiving oxygen. By contrast, no benefit was found in patients without respiratory support 146 .

Tocilizumab and sarilumab, two types of interleukin-6 (IL-6) receptor-specific antibodies previously used to treat various types of arthritis, including rheumatoid arthritis, and cytokine release syndrome, showed effectiveness in the treatment of severe COVID-19 by attenuating the cytokine storm in a small uncontrolled trial 147 . Bevacizumab is an anti-vascular endothelial growth factor (VEGF) medication that could potentially reduce pulmonary oedema in patients with severe COVID-19. Eculizumab is a specific monoclonal antibody that inhibits the proinflammatory complement protein C5. Preliminary results showed that it induced a drop of inflammatory markers and C-reactive protein levels, suggesting its potential to be an option for the treatment of severe COVID-19 (ref. 148 ).

The interferon response is one of the major innate immunity defences against virus invasion. Interferons induce the expression of diverse interferon-stimulated genes, which can interfere with every step of virus replication. Previous studies identified type I interferons as a promising therapeutic candidate for SARS 149 . In vitro data showed SARS-CoV-2 is even more sensitive to type I interferons than SARS-CoV, suggesting the potential effectiveness of type I interferons in the early treatment of COVID-19 (ref. 150 ). In China, vapor inhalation of interferon-α is included in the COVID-19 treatment guideline 151 . Clinical trials are ongoing across the world to evaluate the efficacy of different therapies involving interferons, either alone or in combination with other agents 152 .

Immunoglobulin therapy

Convalescent plasma treatment is another potential adjunctive therapy for COVID-19. Preliminary findings have suggested improved clinical status after the treatment 153 , 154 . The FDA has provided guidance for the use of COVID-19 convalescent plasma under an emergency investigational new drug application. However, this treatment may have adverse effects by causing antibody-mediated enhancement of infection, transfusion-associated acute lung injury and allergic transfusion reactions.

Monoclonal antibody therapy is an effective immunotherapy for the treatment of some viral infections in select patients. Recent studies reported specific monoclonal antibodies neutralizing SARS-CoV-2 infection in vitro and in vivo 155 , 156 , 157 , 158 . Compared with convalescent plasma, which has limited availability and cannot be amplified, monoclonal antibodies can be developed in larger quantities to meet clinical requirements. Hence, they provide the possibility for the treatment and prevention of COVID-19. The neutralizing epitopes of these monoclonal antibodies also offer important information for vaccine design. However, the high cost and limited capacity of manufacturing, as well as the problem of bioavailability, may restrict the wide application of monoclonal antibody therapy.

Vaccination is the most effective method for a long-term strategy for prevention and control of COVID-19 in the future. Many different vaccine platforms against SARS-CoV-2 are in development, the strategies of which include recombinant vectors, DNA, mRNA in lipid nanoparticles, inactivated viruses, live attenuated viruses and protein subunits 159 , 160 , 161 . As of 2 October 2020, ~174 vaccine candidates for COVID-19 had been reported and 51 were in human clinical trials (COVID-19 vaccine and therapeutics tracker ). Many of these vaccine candidates are in phase II testing, and some have already advanced to phase III trials. A randomized double-blinded phase II trial of an adenovirus type 5-vectored vaccine expressing the SARS-CoV-2 S protein, developed by CanSino Biologicals and the Academy of Military Medical Sciences of China, was conducted in 603 adult volunteers in Wuhan. The vaccine has proved to be safe and induced considerable humoral and cellular immune response in most recipients after a single immunization 162 . Another vectored vaccine, ChAdOx1, was developed on the basis of chimpanzee adenovirus by the University of Oxford. In a randomized controlled phase I/II trial, it induced neutralizing antibodies against SARS-CoV-2 in all 1,077 participants after a second vaccine dose, while its safety profile was acceptable as well 163 . The NIAID and Moderna co-manufactured mRNA-1273, a lipid nanoparticle-formulated mRNA vaccine candidate that encodes the stabilized prefusion SARS-CoV-2 S protein. Its immunogenicity has been confirmed by a phase I trial in which robust neutralizing antibody responses were induced in a dose-dependent manner and increased after a second dose 164 . Regarding inactivated vaccines, a successful phase I/II trial involving 320 participants has been reported in China. The whole-virus COVID-19 vaccine had a low rate of adverse reactions and effectively induced neutralizing antibody production 165 . The verified safety and immunogenicity support advancement of these vaccine candidates to phase III clinical trials, which will evaluate their efficacy in protecting healthy populations from SARS-CoV-2 infection.

Future perspectives

COVID-19 is the third highly pathogenic human coronavirus disease to date. Although less deadly than SARS and MERS, the rapid spreading of this highly contagious disease has posed the severest threat to global health in this century. The SARS-CoV-2 outbreak has lasted for more than half a year now, and it is likely that this emerging virus will establish a niche in humans and coexist with us for a long time 166 . Before clinically approved vaccines are widely available, there is no better way to protect us from SARS-CoV-2 than personal preventive behaviours such as social distancing and wearing masks, and public health measures, including active testing, case tracing and restrictions on social gatherings. Despite a flood of SARS-CoV-2 research published every week, current knowledge of this novel coronavirus is just the tip of the iceberg. The animal origin and cross-species infection route of SARS-CoV-2 are yet to be uncovered. The molecular mechanisms of SARS-CoV-2 infection pathogenesis and virus–host interactions remain largely unclear. Intensive studies on these virological profiles of SARS-CoV-2 will provide the basis for the development of preventive and therapeutic strategies against COVID-19. Moreover, continued genomic monitoring of SARS-CoV-2 in new cases is needed worldwide, as it is important to promptly identify any mutation that may result in phenotypic changes of the virus. Finally, COVID-19 is challenging all human beings. Tackling this epidemic is a long-term job which requires efforts of every individual, and international collaborations by scientists, authorities and the public.

Change history

23 february 2022.

A Correction to this paper has been published: https://doi.org/10.1038/s41579-022-00711-2

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Acknowledgements

This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB29010101) and the National Natural Science Foundation of China (31770175).

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Ben Hu, Hua Guo, Peng Zhou & Zheng-Li Shi

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Hu, B., Guo, H., Zhou, P. et al. Characteristics of SARS-CoV-2 and COVID-19. Nat Rev Microbiol 19 , 141–154 (2021). https://doi.org/10.1038/s41579-020-00459-7

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A review on nanoparticles: characteristics, synthesis, applications, and challenges

The significance of nanoparticles (NPs) in technological advancements is due to their adaptable characteristics and enhanced performance over their parent material. They are frequently synthesized by reducing metal ions into uncharged nanoparticles using hazardous reducing agents. However, there have been several initiatives in recent years to create green technology that uses natural resources instead of dangerous chemicals to produce nanoparticles. In green synthesis, biological methods are used for the synthesis of NPs because biological methods are eco-friendly, clean, safe, cost-effective, uncomplicated, and highly productive. Numerous biological organisms, such as bacteria, actinomycetes, fungi, algae, yeast, and plants, are used for the green synthesis of NPs. Additionally, this paper will discuss nanoparticles, including their types, traits, synthesis methods, applications, and prospects.

1. Introduction

Nanotechnology evolved as the achievement of science in the 21st century. The synthesis, management, and application of those materials with a size smaller than 100 nm fall under the interdisciplinary umbrella of this field. Nanoparticles have significant applications in different sectors such as the environment, agriculture, food, biotechnology, biomedical, medicines, etc. like; for treatment of waste water ( Zahra et al., 2020 ), environment monitoring ( Rassaei et al., 2011 ), as a functional food additives ( Chen et al., 2023 ), and as a antimicrobial agents ( Islam et al., 2022 ). Cutting-edge properties of NPs such as; nature, biocompatibility, anti-inflammatory and antibacterial activity, effective drug delivery, bioactivity, bioavailability, tumor targeting, and bio-absorption have led to a growth in the biotechnological, and applied microbiological applications of NPs.

A particle of matter with a diameter of one to one hundred nanometers (nm) is commonly referred to as a nanoparticle or ultrafine particle. Nanoparticles frequently exhibit distinctive size-dependent features, mostly due to their tiny size and colossal surface area. The periodic boundary conditions of the crystalline particle are destroyed when the size of a particle approaches the nano-scale with the characteristic length scale close to or smaller than the de Broglie wavelength or the wavelength of light ( Guo et al., 2013 ). Because of this, many of the physical characteristics of nanoparticles differ significantly from those of bulk materials, leading to a wide range of their novel uses ( Hasan, 2015 ).

2. Emergence of nanotechnology

Nanotechnology emerged in the 1980s due to the convergence of experimental advances such as the invention of the scanning tunneling microscope in 1981 and the discovery of fullerenes in 1985 ( Bayda et al., 2019 ), with the elucidation. The popularization of a conceptual framework for nanotechnology goals began with the publication of the book Engines of Creation in 1986 ( Bayda et al., 2019 ).

2.1. Early stage of NPs

Carbon nanotubes have been discovered in pottery from Keeladi, India, dating from around 600–300 BC ( Bayda et al., 2019 ; Kokarneswaran et al., 2020 ). Cementite nanowires have been discovered in Damascus steel, a material that dates back to around 900 AD; nevertheless, its origin and creation method are unclear ( Kokarneswaran et al., 2020 ). However, it is unknown how they developed or whether the material containing them was used on purpose.

2.2. Discovery of C, Ag, Zn, Cu, and Au nanoparticles

Carbon NPs were found in 1991, and Iijima and Ichihashi announced the single-wall carbon nanotube synthesis with a diameter of 1 nanometer in 1993 ( Chen et al., 2021 ). Carbon nanotubes (CNTs), also known as Bucky tubes, are a kind of nanomaterial made up of a two-dimensional hexagonal lattice of carbon atoms. They are bent one way and joined to produce a hollow cylindrical cylinder. Carbon nanotubes are carbon allotropes that fall between Fullerene (0 dimensional) and Grapheme (2 dimensional) ( Chen et al., 2021 ).

In addition, M. C. Lea reported that the synthesis of citrate-stabilized silver colloid almost 120 years ago ( Nowack et al., 2011 ). This process produces particles with an average diameter of 7 to 9 nm. Nanoscale size and citrate stabilization are analogous to recent findings on nanosilver production employing silver nitrate and citrate ( Majeed Khan et al., 2011 ). The use of proteins to stabilize nanosilver has also been documented as early as 1902 ( Nowack et al., 2011 ; Beyene et al., 2017 ). Since 1897, a nanosilver known as “Collargol” has been made commercially and used for medicinal purposes ( Nowack et al., 2011 ). Collargol, a type of silver nanoparticle, has a particle size of about 10 nanometers (nm). This was determined as early as 1907, and it was found that the diameter of Collargol falls within the nanoscale range. In 1953, Moudry developed a different type of silver nanoparticle called gelatin-stabilized silver nanoparticles, with a diameter ranging from 2–20 nm. These nanoparticles were produced using another method than Collargol. The necessity of nanoscale silver was recognized by the creators of nanosilver formulations decades ago, as seen by the following remark from a patent: “for optimal efficiency, the silver must be disseminated as particles of colloidal size less than 25 nm in crystallite size”( Nowack et al., 2011 ).

Gold NPs (AuNPs) have a long history in chemistry, going back to the Roman era when they were used to decorate glassware by staining them. With the work of Michael Faraday, who may have been the first to notice that colloidal gold solutions have characteristics different from bulk gold, the contemporary age of AuNP synthesis began more than 170 years ago. Michael Faraday investigated the making and factors of colloidal suspensions of “Ruby” gold in 1857. They are among the magnetic nanoparticles due to their distinctive optical and electrical characteristics. Under specific illumination circumstances, Faraday showed how gold nanoparticles might create solutions of various colors ( Bayda et al., 2019 ; Giljohann et al., 2020 ).

3. Classification of NPs

Nanoparticles (NPs) are categorized into the following classes based on their shape, size, and chemical characteristics;

3.1. Carbon-based NPs

Fullerenes and carbon nanotubes (CNTs) are the two essential sub-categories of carbon-based NPs. NPs of globular hollow cages, like allotropic forms of carbon, are found in fullerenes. Due to their electrical conductivity, high strength, structure, electron affinity, and adaptability, they have sparked significant economic interest. These materials have organized pentagonal and hexagonal carbon units, each of which is sp2 hybridized. While CNTs are elongated and form 1–2 nm diameter tubular structures. These fundamentally resemble graphite sheets rolling on top of one another. Accordingly, they are referred to as single-walled (SWNTs), double-walled (DWNTs), or multi-walled carbon nanotubes (MWNTs) depending on how many walls are present in the rolled sheets ( Elliott et al., 2013 ; Astefanei et al., 2015 ).

3.2. Metal NPs

Metal NPs are purely made of metals. These NPs have distinctive electrical properties due to well-known localized surface Plasmon resonance (LSPR) features. Cu, Ag, and Au nanoparticles exhibit a broad absorption band in the visible region of the solar electromagnetic spectrum. Metal NPs are used in several scientific fields because of their enhanced features like facet, size, and shape-controlled synthesis of metal NPs ( Khan et al., 2019 ).

3.3. Ceramics NPs

Ceramic NPs are tiny particles made up of inorganic, non-metallic materials that are heat-treated and cooled in a specific way to give particular properties. They can come in various shapes, including amorphous, polycrystalline, dense, porous, and hollow, and they are known for heat resistance and durable properties. Ceramic NPs are used in various applications, including coating, catalysts, and batteries ( Sigmund et al., 2006 ).

3.4. Lipid-based NPs

These NPs are helpful in several biological applications because they include lipid moieties. Lipid NPs typically have a diameter of 10–1,000 nm and are spherical. Lipid NPs, i.e., polymeric NPs, have a solid lipid core and a matrix consisting of soluble lipophilic molecules ( Khan et al., 2019 ).

3.5. Semiconductor NPs

Semiconductor NPs have qualities similar to metals and non-metals. That is why Semiconductor NPs have unique physical and chemical properties that make them useful for various applications. For example, semiconductor NPs can absorb and emit light and can be used to make more efficient solar cells or brighter light-emitting diodes (LEDs). They can make smaller and faster electronic devices, such as transistors, and can be used in bio imaging and cancer therapy ( Biju et al., 2008 ).

3.6. Polymeric NPs

Polymeric NPs with a size between 1 and 1,000 nm can have active substances surface-adsorbed onto the polymeric core or entrapped inside the polymeric body. These NPs are often organic, and the term polymer nanoparticle (PNP) is commonly used in the literature to refer to them. They resemble Nano spheres or Nano capsules for the most part ( Khan et al., 2019 ; Zielińska et al., 2020 ).

4. Types of different metal-based NPs

Metal NPs are purely made of metal precursors. Due to well-known localized surface plasmon resonance (LSPR) characteristics, these NPs possess unique optoelectrical properties. NPs of the alkali and noble metals, i.e., Cu, Ag, and Au, have a broad absorption band in the visible zone of the solar electromagnetic spectrum. The facet, size, and shape-controlled synthesis of metal NPs are essential in present-day cutting-edge materials ( Dreaden et al., 2012 ; Khan et al., 2019 ).

4.1. Silver nanoparticles (AgNPs)

AgNPs are particles with a size range of 1–100 nanometers made of silver. They have unique physical and chemical properties due to their small size, high surface area-to-volume ratio, and ability to absorb and scatter light in the visible and near-infrared range. Because of their relatively small size and high surface-to-volume ratios, which cause chemical and physical differences in their properties compared to their bulk counterparts, silver nanoparticles may exhibit additional antimicrobial capabilities not exerted by ionic silver ( Shenashen et al., 2014 ).

Besides, AgNPs can be created in various sizes and forms depending on the manufacturing process, the most common of which is chemical reduction. The AgNPs were created by chemically reducing a 12 mM AgNO3 aqueous solution. The reaction was carried out in an argon environment using 70 mL of this solution containing PVP (keeping the molar ratio of the repeating unit of PVP and Ag equal to 34) and 21 mL of Aloe Vera. The mixture was agitated in ultrasonic for 45 min at ambient temperature, then heated 2°C/min to 80°C and left for 2 h to generate a transparent solution with tiny suspended particles that must be removed by simple filtering ( Shenashen et al., 2014 ; Gloria et al., 2017 ).

4.2. Zinc nanoparticles (ZnONPs)

Zinc nanoparticles (ZnONPs) are particles with a size range of 1–100 nm made of zinc. Zinc oxide (ZnO) NPs are a wide band gap semiconductor with a room temperature energy gap of 3.37 eV. Its catalytic, electrical, optoelectronic, and photochemical capabilities have made it widely worthwhile ( Kumar S.S. et al., 2013 ). ZnO nanostructures are ideal for catalytic reaction processes ( Chen and Tang, 2007 ). Laser ablation, hydrothermal methods, electrochemical depositions, sol-gel method, chemical vapor deposition, thermal decomposition, combustion methods, ultrasound, microwave-assisted combustion method, two-step mechanochemical-thermal synthesis, anodization, co-precipitation, electrophoretic deposition, and precipitation processes are some methods for producing ZnO nanoparticles ( Madathil et al., 2007 ; Moghaddam et al., 2009 ; Ghorbani et al., 2015 ).

4.3. Copper nanoparticles (CuNPs)

Copper nanoparticles (CuNPs) comprise a size range of 1–100 nm of copper-based particles ( Khan et al., 2019 ). Cu and Au metal fluorescence have long been known to exist. For excitation at 488 nm, a fluorescence peak centering on the metals’ interband absorption edge has been noted. Additionally, it was noted that the fluorescence peaked at the same energy at two distinct excitation wavelengths (457.9–514.5 and 300–400 nm), and the high-energy tail somewhat grows with increased photon energy pumping. A unique, physical, top-down EEW approach has been used to create Cu nanoparticles. The EEW method involves sending a current of *1,010 A/m2 (1,010 A/m2) across a thin Cu wire, which explodes on a Cu plate for a duration of 10–6 s ( Siwach and Sen, 2008 ).

4.4. Gold nanoparticles (AuNPs)

Gold nanoparticles(AuNPs) are nanometers made of gold. They have unique physical and chemical properties and can absorb and scatter light in the visible and near-infrared range ( Rad et al., 2011 ; Compostella et al., 2017 ).

Scientists around the turn of the 20th century discovered anisotropic AuNPs. Zsigmond ( Li et al., 2014 ) said that gold particles “are not always spherical when their size is 40 nm or lower” in his book, released in 1909. Additionally, he found anisotropic gold particles of various colors. Zsigmondy won the Nobel Prize in 1925 for “his demonstration of the heterogeneous character of colloidal solutions and the methods he utilized” and for developing the ultramicroscope, which allowed him to see the forms of Au particles. He noticed that gold frequently crystallized into a six-sided leaf shape ( Li et al., 2014 ).

AuNPs are the topic of extensive investigation due to their optical, electrical, and molecular-recognition capabilities, with numerous prospective or promised uses in a wide range of fields, including electron microscopy, electronics, nanotechnology, materials science, and biomedicine ( Rad et al., 2011 ).

4.5. Aluminum nanoparticles (AlNPs)

Aluminum nanoparticles (AlNPs) are nanoparticles made of aluminum. Aluminum nanoparticles’ strong reactivity makes them promising for application in high-energy compositions, hydrogen generation in water processes, and the synthesis of alumina 2D and 3D structures ( Lerner et al., 2016 ).

4.6. Iron nanoparticles (FeNPs)

Iron nanoparticles(FeNPs) are particles with a size range of 1−100 nanometers ( Khan et al., 2019 ) made of iron. FeNPs have several potential applications, including their use as catalysts, drug delivery systems, sensors, and energy storage and conversion. They have also been investigated for use in photovoltaic and solar cells and water purification and environmental remediation. FeNPs can also be used in magnetic resonance imaging (MRI) as contrast agents to improve the visibility of tissues and organs. They can also be used in magnetic recording media, such as hard disk drives ( Zhuang and Gentry, 2011 ; Jamkhande et al., 2019 ).

As with any NPs, there are potential health and safety concerns associated with using FeNPs, e.g., FeNPs are used to deliver drugs to specific locations within the body, such as cancer cells and used in MRI, and used to remove contaminants from water ( Farrell et al., 2003 ; Zhuang and Gentry, 2011 ). Tables 1 , ​ ,2 2 show the characteristics of metal-based nanoparticles and the techniques to study their characteristics, respectively.

Characteristics of metal based nanoparticles.

Different analytical techniques and their purposes in studying nanoparticles.

5. Approaches for the synthesis of metal NPs

There are mainly three types of approaches for the synthesis of NPs: the physical, chemical, and biological approaches. The physical approach is also called the top-down approach, while chemical and biological approaches are collectively called the bottom-up approach. The biological approach is also named green systems of NPs. All these approaches are further sub-categorized into various types based upon their method adopted. Figure 1 illustrates each approach’s reported methods for synthesizing NPs.

Approaches of NPs synthesis.

5.1. Top down/physical approach

Bulk materials are fragmented in top-down methods to create nano-structured materials ( Figure 2 ). They are additionally known as physical approaches ( Baig et al., 2021 ). The following techniques can achieve a top-down approach;

Difference between top-down and bottom-up approaches.

5.1.1. Mechanical milling

The mechanical milling process uses balls inside containers and may be carried out in various mills, typically planetary and shaker mills, which is an impact process with high energy ( Gorrasi and Sorrentino, 2015 ). Mechanical milling is a practical approach for creating materials at the nanoscale from bulk materials. Aluminum alloys that have been strengthened by oxide and carbide, spray coatings that are resistant to wear, nanoalloys based on aluminum, nickel, magnesium, and copper, and a variety of other nanocomposite materials may all be created mechanically. A unique class of nanoparticles known as ball-milled carbon nanomaterials has the potential to meet the needs for energy storage, energy conversion, and environmental remediation ( Yadav et al., 2012 ; Lyu et al., 2017 ).

5.1.2. Electrospinning

Typically, it is used to create nanofibers from various materials, most often polymers ( Ostermann et al., 2011 ). A technique for creating fibers called electrospinning draws charged threads from polymer melts or solutions up to fiber sizes of a few hundred nanometers ( Chronakis, 2010 ). Coaxial electrospinning was a significant advancement in the field of electrospinning. The spinneret in coaxial electrospinning is made up of two coaxial capillaries. Core-shell nanoarchitectures may be created in these capillaries using two viscous liquids, a viscous liquid as the shell and a non-viscous liquid as the core ( Du et al., 2012 ). Core-shell and hollow polymer, inorganic, organic, and hybrid materials have all been developed using this technique ( Kumar R. et al., 2013 ).

5.1.3. Laser ablation

A microfeature can be made by employing a laser beam to vaporize a single material ( Tran and Wen, 2014 ). Laser ablation synthesis produces nanoparticles by striking the target material with an intense laser beam. Due to the high intensity of the laser irradiation used in the laser ablation process, the source material or precursor vaporizes, causing the production of nanoparticles ( Amendola and Meneghetti, 2009 ). Laser ablation is an environmentally friendly for producing noble metal nanoparticles ( Baig et al., 2021 ). This method may be used to create a wide variety of nanomaterials, including metal nanoparticles, carbon nanomaterials, oxide composites, and ceramics ( Su and Chang, 2018 ; Baig et al., 2021 ).

5.1.4. Sputtering

Microparticles of a solid material are expelled off its surface during the phenomenon known as sputtering, which occurs when the solid substance is assaulted by intense plasma or gas particles ( Behrisch, 1981 ). According to the incident gaseous ion energy, energetic gaseous ions used in the sputtering deposition process physically expel tiny atom clusters off the target surface ( Muñoz-García et al., 2009 ). The sputtering method is intriguing because it is more affordable than electron-beam lithography, and the composition of the sputtered nanomaterials is similar to the target material with fewer contaminants ( Baig et al., 2021 ).

5.1.5. Electron explosion

In this technique, a thin metal wire is subjected to a high current pulse that causes an explosion, evaporation, and ionization. The metal becomes vaporized and ionized, expands, and cools by reacting with the nearby gas or liquid medium. The condensed vapor finally forms the nanoparticles ( Joh et al., 2013 ). Electron explosion method because it produces plasma from the electrical explosion of a metallic wire, which may produce nanoparticles from a Pt solution without using a reducing agent ( Joh et al., 2013 ).

5.1.6. Sonication

The most crucial step in the creation of nanofluids is sonication. After the mixture has been magnetically stirred in a magnetic stirrer, sonication is performed in an ultrasonication path, ultrasonic vibrator, and mechanical homogenizer. Sonicators have become the industry standard for Probe sonication and are noticeably more powerful and effective when compared to ultrasonic cleaner baths for nanoparticle applications. Probe sonication is highly effective for processing nanomaterials (carbon nanotubes, graphene, inks, metal oxides, etc.) ( Zheng et al., 2010 ).

5.1.7. Pulsed wire discharge method

This is the most used method for creating metal nanoparticles. A pulsating current causes a metal wire to evaporate, producing a vapor that is subsequently cooled by an ambient gas to form nanoparticles. This plan may quickly produce large amounts of energy ( Patil et al., 2021 ).

5.1.8. Arc discharge method

Two graphite rods are adjusted in a chamber with a constant helium pressure during the Arc Discharge procedure. It is crucial to fill the chamber with helium because oxygen or moisture prevents the synthesis of fullerenes. Arc discharge between the ends of the graphite rods drives the vaporization of carbon rods. Achieving new types of nanoparticles depends significantly on the circumstances in which arc discharge occurs. The creation of several nanostructured materials may be accomplished with this technique ( Berkmans et al., 2014 ). It is well-recognized for creating carbon-based materials such as fullerenes, carbon nanohorns (CNHs), carbon nanotubes ( Shi et al., 2000 ), few-layer graphene, and amorphous spherical carbon nanoparticles ( Kumar R. et al., 2013 ).

5.1.9. Lithography

Lithography typically uses a concentrated beam of light or electrons to create nanoparticles, a helpful technique ( Pimpin and Srituravanich, 2012 ). Masked and maskless lithography are the two primary categories of lithography. Without a mask, arbitrary nano-pattern printing is accomplished in maskless lithography. Additionally, it is affordable and easy to apply ( Brady et al., 2019 ).

5.2. Bottom-up approach

Tiny atoms and molecules are combined in bottom-up methods to create nano-structured particles ( Figure 2 ; Baig et al., 2021 ). These include chemical and biological approaches:

5.2.1. Chemical vapor deposition (CVD)

Through a chemical process involving vapor-phase precursors, a thin coating is created on the substrate surface during CVD ( Dikusar et al., 2009 ). Precursors are deemed appropriate for CVD if they exhibit sufficient volatility, high chemical purity, strong evaporation stability, cheap cost, a non-hazardous nature, and long shelf life. Additionally, its breakdown should not leave behind any contaminants. Vapor phase epitaxy, metal-organic CVD, atomic layer epitaxy, and plasma-enhanced CVD are only a few CVD variations. This method’s benefits include producing very pure nanoparticles that are stiff, homogeneous, and strong ( Ago, 2015 ). CVD is an excellent approach to creating high-quality nanomaterials ( Machac et al., 2020 ). It is also well-known for creating two-dimensional nanoparticles ( Baig et al., 2021 ).

5.2.2. Sol-gel process

A wet-chemical approach, called the sol-gel method, is widely utilized to create nanomaterials ( Das and Srivasatava, 2016 ; Baig et al., 2021 ). Metal alkoxides or metal precursors in solution are condensed, hydrolyzed, and thermally decomposed. The result is a stable solution or sol. The gel gains greater viscosity as a result of hydrolysis or condensation. The particle size may be seen by adjusting the precursor concentration, temperature, and pH levels. It may take a few days for the solvent to be removed, for Ostwald ripening to occur, and for the phase to change during the mature stage, which is necessary to enable the growth of solid mass. To create nanoparticles, the unstable chemical ingredients are separated. The generated material is environmentally friendly and has many additional benefits thanks to the sol-gel technique ( Patil et al., 2021 ). The uniform quality of the material generated, the low processing temperature, and the method’s ease in producing composites and complicated nanostructures are just a few of the sol-gel technique’s many advantages ( Parashar et al., 2020 ).

5.2.3. Co-precipitation

It is a solvent displacement technique and is a wet chemical procedure. Ethanol, acetone, hexane, and non-solvent polymers are examples of solvents. Polymer phases can be either synthetic or natural. By mixing the polymer solution, fast diffusion of the polymer-solvent into the non-solvent phase of the polymer results. Interfacial stress at two phases results in the formation of nanoparticles ( Das and Srivasatava, 2016 ). This method’s natural ability to produce high quantities of water-soluble nanoparticles through a straightforward process is one of its key benefits. This process is used to create many commercial iron oxide NP-based MRI contrast agents, including Feridex, Reservist, and Combidex ( Baig et al., 2021 ; Patil et al., 2021 ).

5.2.4. Inert gas condensation/molecular condensation

Metal NPs are produced using this method in large quantities. Making fine NPs using the inactive gas compression approach has been widespread, which creates NPs by causing a metallic source to disappear in an inert gas. At an attainable temperature, metals evaporate at a tolerable pace. Copper metal nanoparticles are created by vaporizing copper metal inside a container containing argon, helium, or neon. The atom quickly loses its energy by cooling the vaporized atom with an inert gas after it boils out. Liquid nitrogen is used to cool the gases, forming nanoparticles in the range of 2–100 nm ( Pérez-Tijerina et al., 2008 ; Patil et al., 2021 ).

5.2.5. Hydrothermal

In this method, for the production of nanoparticles, hydrothermal synthesis uses a wide temperature range from ambient temperature to extremely high temperatures. Comparing this strategy to physical and biological ones offers several benefits. At higher temperature ranges, the nanomaterials produced by hydrothermal synthesis could become unstable ( Banerjee et al., 2008 ; Patil et al., 2021 ).

5.2.6. Green/biological synthesis

The synthesis of diverse metal nanoparticles utilizing bioactive agents, including plant materials, microbes, and various biowastes like vegetable waste, fruit peel waste, eggshell, agricultural waste, algae, and so on, is known as “green” or “biological” nanoparticle synthesis ( Kumari et al., 2021 ). Developing dependable, sustainable green synthesis technologies is necessary to prevent the formation of undesirable or dangerous byproducts ( Figure 3 ). The green synthesis of nanoparticles also has several advantages, including being straightforward, affordable, producing NPs with high stability, requiring little time, producing non-toxic byproducts, and being readily scaled up for large-scale synthesis ( Malhotra and Alghuthaymi, 2022 ).

Schematic diagram for biosynthesis of NPs.

5.2.6.1. Biological synthesis using microorganisms

Microbes use metal capture, enzymatic reduction, and capping to create nanoparticles. Before being converted to nanoparticles by enzymes, metal ions are initially trapped on the surface or interior of microbial cells ( Ghosh et al., 2021 ). Use of microorganisms (especially marine microbes) for synthesis of metalic NPs is environmental friendly, fast and economical ( Patil and Kim, 2018 ). Several microorganisms are used in the synthesis of metal NPs, including:

Biosynthesis of NPs by bacteria: A possible biofactory for producing gold, silver, and cadmium sulfide nanoparticles is thought to be bacterial cells. It is known that bacteria may produce inorganic compounds either inside or outside of their cells ( Hulkoti and Taranath, 2014 ). Desulforibrio caledoiensis ( Qi et al., 2013 ), Enterococcu s sp. ( Rajeshkumar et al., 2014 ), Escherichia coli VM1 ( Maharani et al., 2016 ), and Ochrobactrum anhtropi ( Thomas et al., 2014 ) based metal NPs are reported previously for their potential photocatalytic properties ( Qi et al., 2013 ), antimicrobial activity ( Rajeshkumar et al., 2014 ), and anticancer activity ( Maharani et al., 2016 ).

Extracellular synthesis of NPs by bacteria: The microorganisms’ extracellular reductase enzymes shrink the silver ions to the nanoscale range. According to protein analysis of microorganisms, the NADH-dependent reductase enzyme carries out the bio-reduction of silver ions to AgNPs. The electrons for the reductase enzyme come from NADH, which is subsequently converted to NAD+. The enzyme is also oxidized simultaneously when silver ions are reduced to nanosilver. It has been noted that bio-reduction can occasionally be caused by nitrate-dependent reductase. The decline occurs within a few minutes in the quick extracellular creation of nanoparticles ( Mathew et al., 2010 ). At pH 7, the bacterium R. capsulata produced gold nanoparticles with sizes ranging from 10−20 nm. Numerous nanoplates and spherical gold nanoparticles were produced when the pH was changed to four ( Sriram et al., 2012 ). By adjusting the pH, the gold nanoparticles’ form may be changed. Gold nanoparticle shape was controlled by regulating the proton content at various pH levels. The bacteria R. capsulata ’s release cofactor NADH and NADH-dependent enzymes may cause the bioreduction of Au (3+) to Au (0) and the generation of gold nanoparticles. By using NADH-dependent reductase as an electron carrier, it is possible to start the reduction of gold ions ( Sriram et al., 2012 ).

Intracellular synthesis of NPs by bacteria: Three processes are involved in the intracellular creation of NPs: trapping, bioreduction, and capping. The cell walls of microorganisms and ions charge contribute significantly to creating NPs in the intracellular route. This entails specific ion transit in the presence of enzymes, coenzymes, and other molecules in the microbial cell. Microbes have a range of polysaccharides and proteins in their cell walls, which function as active sites for the binding of metal ions ( Slavin et al., 2017 ). Not all bacteria can produce metal and metal oxide nanoparticles. The only ions that pose a significant hazard to microorganisms are heavy metal ions, which, in response to a threat, cause the germs to react by grabbing or trapping the ions on the cell wall via electrostatic interactions. This occurs because a metal ion is drawn to the cell wall’s carboxylate groups, including cysteine and polypeptides, and certain enzymes with a negative charge ( Zhang et al., 2011 ).

Additionally, the electron transfers from NADH via NADH-dependent educates, which serves as an electron carrier and is located inside the plasma membrane, causing the trapped ions to be reduced into the elemental atom. The nuclei eventually develop into NPs and build up in the cytoplasm or the pre-plasmic space. On the other hand, the stability of NPs is provided by proteins, peptides, and amino acids found inside cells, including cysteine, tyrosine, and tryptophan ( Mohd Yusof et al., 2019 ).

Biosynthesis of NPs by fungi: Because monodisperse nanoparticles with distinct dimensions, various chemical compositions, and sizes may be produced, the biosynthesis of nanoparticles utilizing fungus is frequently employed. Due to the existence of several enzymes in their cells and the ease of handling, fungi are thought to be great candidates for producing metal and metal sulfide nanoparticles ( Mohanpuria et al., 2008 ).

The nanoparticles were created on the surface of the mycelia. After analyzing the results and noting the solution, it was determined that the Ag + ions are initially trapped on the surface of the fungal cells by an electrostatic interaction between gold ions and negatively charged carboxylate groups, which is facilitated by enzymes that are present in the mycelia’s cell wall. Later, the enzymes in the cell wall reduce the silver ions, causing the development of silver nuclei. These nuclei then increase as more Ag ions are reduced and accumulate on them.

The TEM data demonstrate the presence of some silver nanoparticles both on and inside the cytoplasmic membrane. The findings concluded that the Ag ions that permeate through the cell wall were decreased by enzymes found inside the cytoplasm and on the cytoplasmic membrane. Also possible is the diffusion of some silver nanoparticles over the cell wall and eventual cytoplasmic entrapment ( Mukherjee et al., 2001 ; Hulkoti and Taranath, 2014 ).

It was observed that the culture’s age does not affect the shape of the synthesized gold nanoparticles. However, the number of particles decreased when older cells were used. The different pH levels produce a variety of shapes of gold nanoparticles, indicating that pH plays a vital role in determining the shape. The incubation temperature also played an essential role in the accumulation of the gold nanoparticles. It was observed that the particle growth rate was faster at increased temperature levels ( Mukherjee et al., 2001 ; Ahmad et al., 2003 ). The form of the produced gold nanoparticles was shown to be unaffected by the age of the culture. However, when older cells were utilized, the particle count fell. The fact that gold nanoparticles take on various forms at different pH levels suggests that the pH is crucial in determining the shape. The incubation temperature significantly influenced the accumulation of the gold nanoparticles. It was found that higher temperatures caused the particle development rate to accelerate ( Mukherjee et al., 2001 ; Ahmad et al., 2003 ). Verticillium luteoalbum is reported to synthesize gold nanoparticles of 20–40 nm in size ( Erasmus et al., 2014 ). Aspergillus terreus and Penicillium brevicompactum KCCM 60390 based metal NPs are reported for their antimicrobial ( Li G. et al., 2011 ) and cytotoxic activities ( Mishra et al., 2011 ), respectively.

Biosynthesis of NPs using actinomycetes: Actinomycetes have been categorized as prokaryotes since they share significant traits with fungi. They are sometimes referred to as ray fungi ( Mathew et al., 2010 ). Making NPs from actinomycetes is the same as that of fungi ( Sowani et al., 2016 ). Thermomonospora sp., a new species of extremophilic actinomycete, was discovered to produce extracellular, monodispersed, spherical gold nanoparticles with an average size of 8 nm ( Narayanan and Sakthivel, 2010 ). Metal NPs synthesized by Rhodococcus sp. ( Ahmad et al., 2003 ) and Streptomyces sp. Al-Dhabi-87 ( Al-Dhabi et al., 2018 ) are reported for their antimicrobial activities.

Biosynthesis of NPs using algae: Algae have a high concentration of polymeric molecules, and by reducing them, they may hyper-accumulate heavy metal ions and transform them into malleable forms. Algal extracts typically contain pigments, carbohydrates, proteins, minerals, polyunsaturated fatty acids, and other bioactive compounds like antioxidants that are used as stabilizing/capping and reducing agents ( Khanna et al., 2019 ). NPs also have a faster rate of photosynthesis than their biosynthetic counterparts. Live or dead algae are used as model organisms for the environmentally friendly manufacturing process of bio-nanomaterials, such as metallic NPs ( Hasan, 2015 ). Ag and Au are the most extensively researched noble metals to synthesized NPs by algae either intracellularly or extracellularly ( Dahoumane et al., 2017 ). Chlorella vulgaris ( Luangpipat et al., 2011 ), Chlorella pyrenoidosa ( Eroglu et al., 2013 ), Nanochloropsis oculata ( Xia et al., 2013 ), Scenedesmus sp. IMMTCC-25 ( Jena et al., 2014 ) based metal NPs are reported for their potential catalytic ( Luangpipat et al., 2011 ; Eroglu et al., 2013 ) and, antimicrobial ( Eroglu et al., 2013 ; Jena et al., 2014 ) activities along with their use in Li-Ion batteries ( Xia et al., 2013 ).

Intracellular synthesis of NPs using algae: In order to create intracellular NPs, algal biomass must first be gathered and thoroughly cleaned with distilled water. After that, the biomass (living algae) is treated with metallic solutions like AgNO3. The combination is then incubated at a specified pH and a specific temperature for a predetermined time. Finally, it is centrifuged and sonicated to produce the extracted stable NPs ( Uzair et al., 2020 ).

Extracellular synthesis of NPs using algae: Algal biomass is first collected and cleaned with distilled water before being used to synthesize NPs extracellularly ( Uzair et al., 2020 ). The following three techniques are frequently utilized for the subsequent procedure:

(i) A particular amount of time is spent drying the algal biomass (dead algae), after which the dried powder is treated with distilled water and filtered.

(ii) The algal biomass is sonicated with distilled water to get a cell-free extract.

(iii) The resultant product is filtered after the algal biomass has been rinsed with distilled water and incubated for a few hours (8–16 h).

5.2.6.2. Biological synthesis using plant extracts

The substance or active ingredient of the desired quality extracted from plant tissue by treatment for a particular purpose is a plant extract ( Jadoun et al., 2021 ). Plant extracts are combined with a metal salt solution at room temperature to create nanoparticles. Within minutes, the response is finished. This method has been used to create nanoparticles of silver, gold, and many other metals ( Li X. et al., 2011 ). Nanoparticles are biosynthesized using a variety of plants. It is known that the kind of plant extract, its concentration, the concentration of the metal salt, the pH, temperature, and the length of contact time all have an impact on how quickly nanoparticles are produced as well as their number and other properties ( Mittal and Chisti, 2013 ). A leaf extract from Polyalthia longifolia was used to create silver nanoparticles, the average particle size was around 58 nm ( Kumar and Yadav, 2009 ; Kumar et al., 2016 ).

Acacia auriculiformis ( Saini et al., 2016 ), Anisomeles indica ( Govindarajan et al., 2016 ), Azadirachta indica ( Velusamy et al., 2015 ), Bergenia ciliate ( Phull et al., 2016 ), Clitoria ternatea , Solanum nigrum ( Krithiga et al., 2013 ), Coffea arabica ( Dhand et al., 2016 ), Coleus forskohlii ( Naraginti et al., 2016 ), Curculigo orchioides ( Kayalvizhi et al., 2016 ), Digitaria radicosa ( Kalaiyarasu et al., 2016 ), Dioscorea alata ( Pugazhendhi et al., 2016 ), Diospyros paniculata ( Rao et al., 2016 ), Elephantopus scaber ( Kharat and Mendhulkar, 2016 ), Emblica officinalis ( Ramesh et al., 2015 ), Euphorbia antiquorum L. ( Rajkuberan et al., 2017 ), Ficus benghalensis ( Nayak et al., 2016 ), Lantana camara ( Ajitha et al., 2015 ), Cinnamomum zeylanicum ( Soni and Sonam, 2014 ), and Parkia roxburghii ( Paul et al., 2016 ) are the few examples of plants which are reported for the green synthesis of metal NPs (i.e., AgNPs). These were evaluated for their antifilaria activity ( Saini et al., 2016 ), mosquitocidal activity ( Govindarajan et al., 2016 ), antibacterial activity ( Velusamy et al., 2015 ), catalytic activity ( Edison et al., 2016 ), antioxidant activity ( Phull et al., 2016 ), and Cytotoxicity ( Patil et al., 2017 ).

5.2.6.3. Biological synthesis using biomimetic

“Biomimetic synthesis” typically refers to chemical processes that resemble biological synthesis carried out by living things ( Dahoumane et al., 2017 ). In the biomimetic approach, proteins, enzymes, cells, viruses, pollen, and waste biomass are used to synthesize NPs. Two categories are used to classify biomimetic synthesis:

Functional biomimetic synthesis uses various materials and approaches to emulate particular characteristics of natural materials, structures, and systems ( Zan and Wu, 2016 ).

Process biomimetic synthesis is a technique that aims to create different desirable nanomaterials/structures by imitating the synthesis pathways, processes, or procedures of natural chemicals and materials/structures. For instance, several distinctive nano-superstructures (such as satellite structures, dendrimer-like structures, pyramids, cubes, 2D nanoparticle arrays, 3D AuNP tubes, etc.) have been put together in vitro by simulating the protein manufacturing process ( Zan and Wu, 2016 ).

6. Applications of NPs

6.1. applications of nps in environment industry.

Due to their tiny size and distinctive physical and chemical characteristics, NPs appeal to various environmental applications. The properties of nanoparticals and their advantages are illustrated in Figure 4 . The following are some possible NP uses in the environment.

Properties of nanoparticals and their advantages.

6.1.1. Bioremediation

Nanoparticles (NPs) can remove environmental pollutants, such as heavy metals from water or organic contaminants from soil ( Zhuang and Gentry, 2011 ). For example, silver nanoparticles (AgNPs) effectively degrade certain pollutants, such as organic dyes and compounds found in wastewater. Several nanomaterials have been considered for remediation purposes, such as nanoscale zeolites, metal oxides, and carbon nanotubes and fibers ( Zhuang and Gentry, 2011 ). Nanoscale particles used in remediation can access areas that larger particles cannot. They can be coated to facilitate transport and prevent reaction with surrounding soil matrices before reacting with contaminants. One widely used nanomaterial for remediation is Nanoscale zerovalent iron (nZVI). It has been used at several hazardous waste sites to clean up chlorinated solvents that have contaminated groundwater ( Elliott et al., 2013 ). Removing heavy metals such as mercury, lead, thallium, cadmium, and arsenic from natural water has attracted considerable attention because of their adverse effects on environmental and human health. Superparamagnetic iron oxide NPs are an effective sorbent material for this toxic soft material. So, no measurements of engineered NPs in the environment have been available due to the absence of analytical methods able to quantify the trace concentration of NPs ( Elliott et al., 2013 ).

6.1.2. Sensors in environment

Nanotechnology/NPs are already being used to improve water quality and assist in environmental clean-up activities ( Pradeep, 2009 ). Their potential use as environmental sensors to monitor pollutants is also becoming viable NPs can be used as sensors to detect the presence of certain compounds in the environment, such as heavy metals or pollutants. The nano-sensors small size and wide detection range provide great flexibility in practical applications. It has been reported that nanoscale sensors can be used to detect microbial pathogens and biological compounds, such as toxins, in aqueous environments ( Yadav et al., 2010 ). NPS can be designed to selectively bind to specific types of pollutants, allowing them to be detected at low concentrations. For example, gold nanoparticles (AuNPs) have been used as sensors for the detection of mercury in water ( Theron et al., 2010 ).

6.1.3. Catalysts in environment

Nanoparticles (NPs) are used as catalysts in chemical reactions, such as in the production of biofuels or environmental remediation processes, and to catalyze biomass conversion into fuels, such as ethanol or biodiesel. For example, platinum nanoparticles (PtNPs) have been explored for use in the production of biofuels due to their ability to catalyze the conversion of biomass into fuels ( Lam and Luong, 2014 ). PtNPs also showed promising sensing properties; for example, Using Pt NPs, the Hg ions were quantified in the range of 50–500 nM in MilliQ, tap, and groundwater samples, and the limit of quantifications for Hg ions were 16.9, 26, and 47.3 nM. The biogenic PtNPs-based probe proved to be applicable for detecting and quantifying Hg ions ( Kora and Rastogi, 2018 ).

Overall, NPs have significant potential for use in the environment and are being actively researched for a variety of applications.

6.2. Applications of NPs in medicine industry

Nanoparticles (NPs) have unique physical and chemical properties due to their small size, making them attractive for use in various applications, including the medicine industry. Some potential applications of NPs in medicine include:

6.2.1. Drug delivery

Technological interest has been given to AuNPs due to their unique optical properties, ease of synthesis, and chemical stability. The particles can be used in biomedical applications such as cancer treatment ( Sun et al., 2014 ), biological imaging ( Abdulle and Chow, 2019 ), chemical sensing, and drug delivery. Sun et al. (2014) mentioned in detail about two different methods of controlled release of drugs associated with NPs, which were (1) sustained (i.e., diffusion-controlled and erosion-controlled) and (2) stimuli-responsive (i.e., pH-sensitive, enzyme-sensitive, thermoresponsive, and photosensitive). Figure 5 illustrates that how NPs acts as targeted delivery of medicines to treat cancer cells ( Figure 5A ) and therapeutic gene delivery to synthesis proteins of interests in targeted cells ( Figure 5B ). NPs can deliver drugs to specific body areas, allowing for more targeted and effective treatment ( Siddique and Chow, 2020 ). For example AgNPs have been explored for use in drug delivery due to their stability and ability to accumulate in certain types of cancerous tumors ( Siddique and Chow, 2020 ). ZnONPs have also been explored for drug delivery due to their ability to selectively target cancer cells ( Anjum et al., 2021 ). CuNPs have been shown to have antimicrobial properties and are being explored for drug delivery to treat bacterial infections ( Yuan et al., 2018 ). AuNPs have unique optical, electrical, and catalytic properties and are being explored for drug delivery due to their ability to accumulate in certain cancerous tumors. Silver NPs (AgNPs) have been incorporated into wound dressings, bone cement, and implants ( Schröfel et al., 2014 ).

Application of nanoparticles as; targated drug delivery (A) , and therapeutic protein generation in targated cells (B) .

6.2.2. Diagnostics

Nanoparticles (NPs) can be used as imaging agents to help visualize specific body areas. For example, iron oxide nanoparticles (Fe 3 O 4 NPs) have been used as magnetic resonance imaging (MRI) contrast agents to help visualize tissues and organs ( Nguyen et al., 2013 ). AuNPs have unique optical, electrical, and catalytic properties and are being explored for diagnostics due to their ability to accumulate in certain cancerous tumors ( Siddique and Chow, 2020 ).

6.2.3. Tissue engineering

Nanoparticles (NPs) can help stimulate the growth and repair of tissues and organs. For example, titanium dioxide nanoparticles (TiO2 NPs) have been explored for tissue engineering due to their ability to stimulate the growth of bone cells ( Kim et al., 2014 ).

6.2.4. Antimicrobials

Some NPs, such as silver nanoparticles (AgNPs) and copper nanoparticles (CuNPs), have strong antimicrobial properties and are being explored for use in a variety of medical products, such as wound dressings and medical devices ( Hoseinzadeh et al., 2017 ).

Overall, NPs have significant potential for use in the medical industry and are being actively researched for various applications. However, it is essential to carefully consider the potential risks and benefits of using NPs in medicine and ensure their safe and responsible use.

6.3. Applications of NPs in agriculture industry

There are several ways in which nanoparticles (NPs) have the potential to alter the agricultural sector. NPs may be used in agriculture for a variety of reasons, including:

6.3.1. Pesticides and herbicides

Nanoparticles (NPs) can be used to deliver pesticides and herbicides in a targeted manner, reducing the number of chemicals needed and minimizing the potential for environmental contamination ( Khan et al., 2019 ). AgNPs and CuNPs have antimicrobial properties, making them potentially useful for controlling pests and diseases in crops. They can also be used as delivery systems for active ingredients, allowing for more targeted application and reducing the potential for environmental contamination ( Hoseinzadeh et al., 2017 ; Dangi and Verma, 2021 ).

It is important to note that using metal NPs in pesticides and herbicides is still in the early stages of development. More research is needed to understand their potential impacts on human health and the environment ( Dangi and Verma, 2021 ).

6.3.2. Fertilizers and plant growth

Nano fertilizers offer an opportunity for efficiently improving plant mineral nutrition. Some studies have shown that nanomaterials can be more effective than conventional fertilizers, with a controlled release of nutrients increasing the efficiency of plant uptake and potentially reducing adverse environmental outcomes associated with the loss of nutrients in the broader environment. However, other studies have found that nanomaterial has the same or even less effective effectiveness than conventional fertilizers. NPs used to deliver fertilizers to plants more efficiently, reducing the amount of fertilizer needed, and reducing the risk of nutrient runoff ( Kopittke et al., 2019 ).

Ag ( Jaskulski et al., 2022 ), Zn ( Song and Kim, 2020 ), Cu, Au, Al, and Fe ( Kopittke et al., 2019 ) based NPs have been shown to have fertilizing properties and plant growth-promoting properties, and may help provide essential nutrients to plants and improve plant growth and yield. It is important to note that the use of NPs in fertilizers is still in the early stages of development. More research is needed to understand their potential impacts on human health and the environment.

6.3.3. Food safety

Nanoparticles (NPs) can detect and eliminate pathogens in food products, improving food safety, and reducing the risk of foodborne illness ( Zhuang and Gentry, 2011 ).

6.3.4. Water purification

Nanoparticles (NPs) can purify irrigation water, reducing the risk of crop contamination and improving crop yield ( Zhuang and Gentry, 2011 ). Using NPs in agriculture can improve crop yields, reduce agriculture’s environmental impact, and improve food products’ safety and quality.

6.4. Applications of NPs in food industry

Numerous applications for nanoparticles (NPs) in the food sector are possible, including:

6.4.1. Food processing and food preservation/food packaging

Nanoparticles (NPs) can be used to improve the efficiency and performance of food processing operations, such as grinding, mixing, and drying, e.g., AgNPs have been used as a natural antimicrobial agent in food processing operations, helping to prevent the growth of bacteria and other microorganisms ( Dangi and Verma, 2021 ) and also NPs are used to enhance the performance of materials used in food packaging, making them more resistant to pollutants like moisture and gases.

6.4.2. Food fortification

Nanoparticles (NPs) can deliver essential nutrients to food products, such as vitamins and minerals, more efficiently and effectively. e.g., Fe 2 O 3 , and CuNPs have been used to fortify food products with iron, and Cu is an essential nutrient necessary for the metabolism of iron and other nutrients. Iron is an essential nutrient often lacking in many people’s diets, particularly in developing countries ( Kopittke et al., 2019 ).

6.4.3. Sensors

Nanoparticles (NPs) used to improve the sensitivity and specificity of food sensors, allowing them to detect a broader range of substances or signals ( Yadav et al., 2010 ).

Overall, using NPs in the food industry can improve the performance, safety, and nutritional value of a wide range of food products and processes.

6.5. Applications of NPs in electronics industry and automotive industry

In many aspects, nanoparticles (NPs) can transform the electronics sector. NPs may be used in a variety of electrical applications, such as:

6.5.1. Display technologies/storage devices

Nanoparticles (NPs) can be used to improve the performance of displays ( Park and Choi, 2019 ; Bahadur et al., 2021 ; Triana et al., 2022 ), such as LCD and OLED displays, by enhancing the brightness, color, and contrast of the image, such as silver NPs and gold NPs, have been explored for use in LCD and OLED displays as a means of improving the conductivity of the display ( Gwynne, 2020 ). NPs improve the performance and durability of energy storage devices, such as batteries and supercapacitors, by increasing energy density and charging speed. Zinc oxide nanoparticles (ZnO NPs) have the potential to be used in energy storage devices, such as batteries and supercapacitors, due to their ability to store and release energy ( Singh et al., 2011 ).

6.5.2. Data storage

Nanoparticles (NPs) can improve the capacity and speed of data storage devices, such as hard drives and flash drives. Magnetic NPs, such as iron oxide NPs, have been explored for use in data storage devices, such as hard drives, due to their ability to store, and retrieve data using magnetism. These NPs are often composed of a magnetic metal, such as iron, cobalt, or nickel. They can be magnetized and demagnetized, allowing them to store and retrieve data ( Ahmad et al., 2021 ).

Overall, the use of NPs in electronics has the potential to improve the performance and efficiency of a wide range of electronic devices and systems.

Applications of NPs in chemical industry: The chemical industry might be entirely transformed by nanoparticles (NPs) in various ways. The following are potential uses for NPs in the chemical industry ( Salem and Fouda, 2021 ).

6.5.3. Chemical processing/catalysis

Nanoparticles (NPs) can be used as catalysts in chemical reactions, allowing them to be carried out more efficiently and at lower temperatures. Some examples of metal NPs that have been used as catalysts in the chemical industry include: PtNPs have been used as catalysts in a variety of chemical reactions, including fuel cell reactions ( Bhavani et al., 2021 ), hydrogenation reactions, and oxidation reactions ( Lara and Philippot, 2014 ), PdNPs have been used as catalysts in a variety of chemical reactions, including hydrogenation reactions and cross-coupling reactions ( Pérez-Lorenzo, 2012 ), FeNPs have been used as catalysts in a variety of chemical reactions, including hydrolysis reactions ( Jiang and Xu, 2011 ), and oxygen reduction reactions, NiNPs have been used as catalysts in a variety of chemical reactions, including hydrogenation reactions, and hydrolysis reactions ( Salem and Fouda, 2021 ).

6.5.4. Separation and purification

NPs are used to separate and purify chemicals and other substances, such as gases and liquids, by exploiting their size-based properties ( Hollamby et al., 2010 ). Several types of metal nanoparticles (NPs) have been explored for use in separation and purification processes in the chemical industry, including Fe 2 O 3 NPs have been used to separate and purify gases, liquids, and chemicals. They have also been used to remove contaminants from water ( Pradeep, 2009 ; Siddique and Chow, 2020 ). AgNPs have been used to purify water and remove contaminants ( Pradeep, 2009 ), such as bacteria and viruses. They have also been used to remove heavy metals from water and other substances ( Zhuang and Gentry, 2011 ). AuNPs have been used to purify water and remove contaminants, such as bacteria and viruses ( Siddique and Chow, 2020 ). They have also been used to separate and purify gases and liquids ( Zhuang and Gentry, 2011 ). AlNPs have been used to remove contaminants from water and other substances, such as oils and fuels. They have also been used to purify gases ( Zhuang and Gentry, 2011 ).

6.6. Applications of NPs in defense industry

Nanoparticles (NPs) can be used to improve the efficiency and performance of chemical processing operations, such as refining and synthesizing chemicals ( Schröfel et al., 2014 ). Nanoparticles (NPs) have the potential to be used in the defense industry in several ways, including:

6.6.1. Sensors

Nanoparticles (NPs) can improve the sensitivity and specificity of sensors used in defense systems, such as sensors for detecting chemical, biological, or radiological threats ( Zheng et al., 2010 ).

6.6.2. Protective coatings

Nanoparticles (NPs) can improve the performance and durability of protective coatings applied to defense equipment, such as coatings resistant to chemical or biological agents. For example, metal NPs can improve the mechanical properties and durability of the coating, making it more resistant to wear and corrosion. For example, adding Al or Zn based NPs to a polymer coating can improve its corrosion resistance. In contrast, adding Ni or Cr-based NPs can improve their wear resistance ( Rangel-Olivares et al., 2021 ).

6.6.3. Weapons

Nanoparticles (NPs) are used as weapons against viruses, bacteria, etc, ( Ye et al., 2020 ) and as well as in the development of armor and protective materials. There have been some reports of the potential use of NPs in military and defense applications, such as in the development of armor and protective materials. For example, adding nanoparticles, such as ceramic or metal NPs, to polymers or other materials can improve their mechanical properties and make them more resistant to damage. In addition, there have been reports of the use of NPs in developing sensors and detection systems for defense purposes.

6.6.4. Manufacturing

Nanoparticles (NPs) can improve the performance and durability of materials used in defense equipment, such as armor or structural materials. Metal NPs can be used in materials by adding them as a filler or reinforcement in polymers. For example, the addition of metal NPs such as aluminum (Al), copper (Cu), or nickel (Ni) to polymers can improve the mechanical properties, thermal stability, and electrical conductivity of the resulting composite material ( Khan et al., 2019 ).

Metal NPs can also make functional materials, such as catalysts and sensors. For example, metal NPs, such as gold (Au), and platinum (Pt), can be used as catalysts in various chemical reactions due to their high surface area and ability to adsorb reactants ( Zheng et al., 2010 ).

6.6.5. Energy storage

Nanoparticles (NPs) can improve the performance and efficiency of energy storage systems used in defense systems, such as batteries or fuel cells ( Morsi et al., 2022 ). In batteries, nanoparticles can be used as a cathode material to increase the battery’s energy density, rate capability, and cycling stability. For example, lithium cobalt oxide (LiCoO 2 ) nanoparticles have been used as cathode materials in lithium-ion batteries due to their high capacity and good rate performance. In addition, nanoparticles of transition metal oxides, such as iron oxide (Fe 2 O 3 ), and manganese oxide (MnO 2 ), have been used as cathode materials in rechargeable lithium batteries due to their high capacity and good rate performance. In supercapacitors, nanoparticles can be used as the active material in the electrodes to increase the specific surface area, leading to an increase in the device’s capacitance ( Morsi et al., 2022 ). Using NPs in the defense industry can improve defense systems’ performance, efficiency, and safety.

7. Future perspectives

Metal nanoparticles (NPs) have many potential applications in various fields, including electronics, energy storage, catalysis, and medicine. However, there are also several challenges and potential future directions for developing and using metal NPs.

One major challenge is synthesizing and processing metal NPs with precise size and shape control. Many methods for synthesizing metal NPs involve high temperatures and harsh chemical conditions, which can be challenging to scale up for large-scale production. In addition, the size and shape of metal NPs can significantly impact their properties and potential applications, so it is essential to synthesize NPs with precise size and shape control.

Another challenge is the environmental impact of metal NPs. Some metal NPs, such as silver NPs, can be toxic to aquatic life and may have other environmental impacts. There is a need for more research on the environmental effects of metal NPs and the development of more environmentally friendly (Green) synthesis and processing methods.

In terms of future directions, one promising area is the use of metal NPs for energy storage, conversion, and protection of the environment. For example, metal NPs could be used to improve batteries’ performance or develop more efficient solar cells. In addition, metal NPs could be used in catalysis to improve the efficiency of chemical reactions. There is also ongoing research on metal NPs in medicine, including drug delivery and cancer therapy.

Author contributions

KAA: conceptualization, methodology, validation, formal analysis, investigation, writing – original draft, writing – review and editing, and visualization.

Acknowledgments

The author thanks Prof. Dr. Mona M. Sobhy, Department of Reproductive Diseases, Animal Reproduction Research Institute, ARC, Giza, Egypt, and Dr. Omar Hewedy, University of Guelph, Canada, for the critical reading of the manuscript.

Conflict of interest

The author declares that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Publisher’s note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.

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