problems with single case studies

The Advantages and Limitations of Single Case Study Analysis

As Andrew Bennett and Colin Elman have recently noted, qualitative research methods presently enjoy “an almost unprecedented popularity and vitality… in the international relations sub-field”, such that they are now “indisputably prominent, if not pre-eminent” (2010: 499). This is, they suggest, due in no small part to the considerable advantages that case study methods in particular have to offer in studying the “complex and relatively unstructured and infrequent phenomena that lie at the heart of the subfield” (Bennett and Elman, 2007: 171). Using selected examples from within the International Relations literature[1], this paper aims to provide a brief overview of the main principles and distinctive advantages and limitations of single case study analysis. Divided into three inter-related sections, the paper therefore begins by first identifying the underlying principles that serve to constitute the case study as a particular research strategy, noting the somewhat contested nature of the approach in ontological, epistemological, and methodological terms. The second part then looks to the principal single case study types and their associated advantages, including those from within the recent ‘third generation’ of qualitative International Relations (IR) research. The final section of the paper then discusses the most commonly articulated limitations of single case studies; while accepting their susceptibility to criticism, it is however suggested that such weaknesses are somewhat exaggerated. The paper concludes that single case study analysis has a great deal to offer as a means of both understanding and explaining contemporary international relations.

The term ‘case study’, John Gerring has suggested, is “a definitional morass… Evidently, researchers have many different things in mind when they talk about case study research” (2006a: 17). It is possible, however, to distil some of the more commonly-agreed principles. One of the most prominent advocates of case study research, Robert Yin (2009: 14) defines it as “an empirical enquiry that investigates a contemporary phenomenon in depth and within its real-life context, especially when the boundaries between phenomenon and context are not clearly evident”. What this definition usefully captures is that case studies are intended – unlike more superficial and generalising methods – to provide a level of detail and understanding, similar to the ethnographer Clifford Geertz’s (1973) notion of ‘thick description’, that allows for the thorough analysis of the complex and particularistic nature of distinct phenomena. Another frequently cited proponent of the approach, Robert Stake, notes that as a form of research the case study “is defined by interest in an individual case, not by the methods of inquiry used”, and that “the object of study is a specific, unique, bounded system” (2008: 443, 445). As such, three key points can be derived from this – respectively concerning issues of ontology, epistemology, and methodology – that are central to the principles of single case study research.

First, the vital notion of ‘boundedness’ when it comes to the particular unit of analysis means that defining principles should incorporate both the synchronic (spatial) and diachronic (temporal) elements of any so-called ‘case’. As Gerring puts it, a case study should be “an intensive study of a single unit… a spatially bounded phenomenon – e.g. a nation-state, revolution, political party, election, or person – observed at a single point in time or over some delimited period of time” (2004: 342). It is important to note, however, that – whereas Gerring refers to a single unit of analysis – it may be that attention also necessarily be given to particular sub-units. This points to the important difference between what Yin refers to as an ‘holistic’ case design, with a single unit of analysis, and an ’embedded’ case design with multiple units of analysis (Yin, 2009: 50-52). The former, for example, would examine only the overall nature of an international organization, whereas the latter would also look to specific departments, programmes, or policies etc.

Secondly, as Tim May notes of the case study approach, “even the most fervent advocates acknowledge that the term has entered into understandings with little specification or discussion of purpose and process” (2011: 220). One of the principal reasons for this, he argues, is the relationship between the use of case studies in social research and the differing epistemological traditions – positivist, interpretivist, and others – within which it has been utilised. Philosophy of science concerns are obviously a complex issue, and beyond the scope of much of this paper. That said, the issue of how it is that we know what we know – of whether or not a single independent reality exists of which we as researchers can seek to provide explanation – does lead us to an important distinction to be made between so-called idiographic and nomothetic case studies (Gerring, 2006b). The former refers to those which purport to explain only a single case, are concerned with particularisation, and hence are typically (although not exclusively) associated with more interpretivist approaches. The latter are those focused studies that reflect upon a larger population and are more concerned with generalisation, as is often so with more positivist approaches[2]. The importance of this distinction, and its relation to the advantages and limitations of single case study analysis, is returned to below.

Thirdly, in methodological terms, given that the case study has often been seen as more of an interpretivist and idiographic tool, it has also been associated with a distinctly qualitative approach (Bryman, 2009: 67-68). However, as Yin notes, case studies can – like all forms of social science research – be exploratory, descriptive, and/or explanatory in nature. It is “a common misconception”, he notes, “that the various research methods should be arrayed hierarchically… many social scientists still deeply believe that case studies are only appropriate for the exploratory phase of an investigation” (Yin, 2009: 6). If case studies can reliably perform any or all three of these roles – and given that their in-depth approach may also require multiple sources of data and the within-case triangulation of methods – then it becomes readily apparent that they should not be limited to only one research paradigm. Exploratory and descriptive studies usually tend toward the qualitative and inductive, whereas explanatory studies are more often quantitative and deductive (David and Sutton, 2011: 165-166). As such, the association of case study analysis with a qualitative approach is a “methodological affinity, not a definitional requirement” (Gerring, 2006a: 36). It is perhaps better to think of case studies as transparadigmatic; it is mistaken to assume single case study analysis to adhere exclusively to a qualitative methodology (or an interpretivist epistemology) even if it – or rather, practitioners of it – may be so inclined. By extension, this also implies that single case study analysis therefore remains an option for a multitude of IR theories and issue areas; it is how this can be put to researchers’ advantage that is the subject of the next section.

Having elucidated the defining principles of the single case study approach, the paper now turns to an overview of its main benefits. As noted above, a lack of consensus still exists within the wider social science literature on the principles and purposes – and by extension the advantages and limitations – of case study research. Given that this paper is directed towards the particular sub-field of International Relations, it suggests Bennett and Elman’s (2010) more discipline-specific understanding of contemporary case study methods as an analytical framework. It begins however, by discussing Harry Eckstein’s seminal (1975) contribution to the potential advantages of the case study approach within the wider social sciences.

Eckstein proposed a taxonomy which usefully identified what he considered to be the five most relevant types of case study. Firstly were so-called configurative-idiographic studies, distinctly interpretivist in orientation and predicated on the assumption that “one cannot attain prediction and control in the natural science sense, but only understanding ( verstehen )… subjective values and modes of cognition are crucial” (1975: 132). Eckstein’s own sceptical view was that any interpreter ‘simply’ considers a body of observations that are not self-explanatory and “without hard rules of interpretation, may discern in them any number of patterns that are more or less equally plausible” (1975: 134). Those of a more post-modernist bent, of course – sharing an “incredulity towards meta-narratives”, in Lyotard’s (1994: xxiv) evocative phrase – would instead suggest that this more free-form approach actually be advantageous in delving into the subtleties and particularities of individual cases.

Eckstein’s four other types of case study, meanwhile, promote a more nomothetic (and positivist) usage. As described, disciplined-configurative studies were essentially about the use of pre-existing general theories, with a case acting “passively, in the main, as a receptacle for putting theories to work” (Eckstein, 1975: 136). As opposed to the opportunity this presented primarily for theory application, Eckstein identified heuristic case studies as explicit theoretical stimulants – thus having instead the intended advantage of theory-building. So-called p lausibility probes entailed preliminary attempts to determine whether initial hypotheses should be considered sound enough to warrant more rigorous and extensive testing. Finally, and perhaps most notably, Eckstein then outlined the idea of crucial case studies , within which he also included the idea of ‘most-likely’ and ‘least-likely’ cases; the essential characteristic of crucial cases being their specific theory-testing function.

Whilst Eckstein’s was an early contribution to refining the case study approach, Yin’s (2009: 47-52) more recent delineation of possible single case designs similarly assigns them roles in the applying, testing, or building of theory, as well as in the study of unique cases[3]. As a subset of the latter, however, Jack Levy (2008) notes that the advantages of idiographic cases are actually twofold. Firstly, as inductive/descriptive cases – akin to Eckstein’s configurative-idiographic cases – whereby they are highly descriptive, lacking in an explicit theoretical framework and therefore taking the form of “total history”. Secondly, they can operate as theory-guided case studies, but ones that seek only to explain or interpret a single historical episode rather than generalise beyond the case. Not only does this therefore incorporate ‘single-outcome’ studies concerned with establishing causal inference (Gerring, 2006b), it also provides room for the more postmodern approaches within IR theory, such as discourse analysis, that may have developed a distinct methodology but do not seek traditional social scientific forms of explanation.

Applying specifically to the state of the field in contemporary IR, Bennett and Elman identify a ‘third generation’ of mainstream qualitative scholars – rooted in a pragmatic scientific realist epistemology and advocating a pluralistic approach to methodology – that have, over the last fifteen years, “revised or added to essentially every aspect of traditional case study research methods” (2010: 502). They identify ‘process tracing’ as having emerged from this as a central method of within-case analysis. As Bennett and Checkel observe, this carries the advantage of offering a methodologically rigorous “analysis of evidence on processes, sequences, and conjunctures of events within a case, for the purposes of either developing or testing hypotheses about causal mechanisms that might causally explain the case” (2012: 10).

Harnessing various methods, process tracing may entail the inductive use of evidence from within a case to develop explanatory hypotheses, and deductive examination of the observable implications of hypothesised causal mechanisms to test their explanatory capability[4]. It involves providing not only a coherent explanation of the key sequential steps in a hypothesised process, but also sensitivity to alternative explanations as well as potential biases in the available evidence (Bennett and Elman 2010: 503-504). John Owen (1994), for example, demonstrates the advantages of process tracing in analysing whether the causal factors underpinning democratic peace theory are – as liberalism suggests – not epiphenomenal, but variously normative, institutional, or some given combination of the two or other unexplained mechanism inherent to liberal states. Within-case process tracing has also been identified as advantageous in addressing the complexity of path-dependent explanations and critical junctures – as for example with the development of political regime types – and their constituent elements of causal possibility, contingency, closure, and constraint (Bennett and Elman, 2006b).

Bennett and Elman (2010: 505-506) also identify the advantages of single case studies that are implicitly comparative: deviant, most-likely, least-likely, and crucial cases. Of these, so-called deviant cases are those whose outcome does not fit with prior theoretical expectations or wider empirical patterns – again, the use of inductive process tracing has the advantage of potentially generating new hypotheses from these, either particular to that individual case or potentially generalisable to a broader population. A classic example here is that of post-independence India as an outlier to the standard modernisation theory of democratisation, which holds that higher levels of socio-economic development are typically required for the transition to, and consolidation of, democratic rule (Lipset, 1959; Diamond, 1992). Absent these factors, MacMillan’s single case study analysis (2008) suggests the particularistic importance of the British colonial heritage, the ideology and leadership of the Indian National Congress, and the size and heterogeneity of the federal state.

Most-likely cases, as per Eckstein above, are those in which a theory is to be considered likely to provide a good explanation if it is to have any application at all, whereas least-likely cases are ‘tough test’ ones in which the posited theory is unlikely to provide good explanation (Bennett and Elman, 2010: 505). Levy (2008) neatly refers to the inferential logic of the least-likely case as the ‘Sinatra inference’ – if a theory can make it here, it can make it anywhere. Conversely, if a theory cannot pass a most-likely case, it is seriously impugned. Single case analysis can therefore be valuable for the testing of theoretical propositions, provided that predictions are relatively precise and measurement error is low (Levy, 2008: 12-13). As Gerring rightly observes of this potential for falsification:

“a positivist orientation toward the work of social science militates toward a greater appreciation of the case study format, not a denigration of that format, as is usually supposed” (Gerring, 2007: 247, emphasis added).

In summary, the various forms of single case study analysis can – through the application of multiple qualitative and/or quantitative research methods – provide a nuanced, empirically-rich, holistic account of specific phenomena. This may be particularly appropriate for those phenomena that are simply less amenable to more superficial measures and tests (or indeed any substantive form of quantification) as well as those for which our reasons for understanding and/or explaining them are irreducibly subjective – as, for example, with many of the normative and ethical issues associated with the practice of international relations. From various epistemological and analytical standpoints, single case study analysis can incorporate both idiographic sui generis cases and, where the potential for generalisation may exist, nomothetic case studies suitable for the testing and building of causal hypotheses. Finally, it should not be ignored that a signal advantage of the case study – with particular relevance to international relations – also exists at a more practical rather than theoretical level. This is, as Eckstein noted, “that it is economical for all resources: money, manpower, time, effort… especially important, of course, if studies are inherently costly, as they are if units are complex collective individuals ” (1975: 149-150, emphasis added).

Limitations

Single case study analysis has, however, been subject to a number of criticisms, the most common of which concern the inter-related issues of methodological rigour, researcher subjectivity, and external validity. With regard to the first point, the prototypical view here is that of Zeev Maoz (2002: 164-165), who suggests that “the use of the case study absolves the author from any kind of methodological considerations. Case studies have become in many cases a synonym for freeform research where anything goes”. The absence of systematic procedures for case study research is something that Yin (2009: 14-15) sees as traditionally the greatest concern due to a relative absence of methodological guidelines. As the previous section suggests, this critique seems somewhat unfair; many contemporary case study practitioners – and representing various strands of IR theory – have increasingly sought to clarify and develop their methodological techniques and epistemological grounding (Bennett and Elman, 2010: 499-500).

A second issue, again also incorporating issues of construct validity, concerns that of the reliability and replicability of various forms of single case study analysis. This is usually tied to a broader critique of qualitative research methods as a whole. However, whereas the latter obviously tend toward an explicitly-acknowledged interpretive basis for meanings, reasons, and understandings:

“quantitative measures appear objective, but only so long as we don’t ask questions about where and how the data were produced… pure objectivity is not a meaningful concept if the goal is to measure intangibles [as] these concepts only exist because we can interpret them” (Berg and Lune, 2010: 340).

The question of researcher subjectivity is a valid one, and it may be intended only as a methodological critique of what are obviously less formalised and researcher-independent methods (Verschuren, 2003). Owen (1994) and Layne’s (1994) contradictory process tracing results of interdemocratic war-avoidance during the Anglo-American crisis of 1861 to 1863 – from liberal and realist standpoints respectively – are a useful example. However, it does also rest on certain assumptions that can raise deeper and potentially irreconcilable ontological and epistemological issues. There are, regardless, plenty such as Bent Flyvbjerg (2006: 237) who suggest that the case study contains no greater bias toward verification than other methods of inquiry, and that “on the contrary, experience indicates that the case study contains a greater bias toward falsification of preconceived notions than toward verification”.

The third and arguably most prominent critique of single case study analysis is the issue of external validity or generalisability. How is it that one case can reliably offer anything beyond the particular? “We always do better (or, in the extreme, no worse) with more observation as the basis of our generalization”, as King et al write; “in all social science research and all prediction, it is important that we be as explicit as possible about the degree of uncertainty that accompanies out prediction” (1994: 212). This is an unavoidably valid criticism. It may be that theories which pass a single crucial case study test, for example, require rare antecedent conditions and therefore actually have little explanatory range. These conditions may emerge more clearly, as Van Evera (1997: 51-54) notes, from large-N studies in which cases that lack them present themselves as outliers exhibiting a theory’s cause but without its predicted outcome. As with the case of Indian democratisation above, it would logically be preferable to conduct large-N analysis beforehand to identify that state’s non-representative nature in relation to the broader population.

There are, however, three important qualifiers to the argument about generalisation that deserve particular mention here. The first is that with regard to an idiographic single-outcome case study, as Eckstein notes, the criticism is “mitigated by the fact that its capability to do so [is] never claimed by its exponents; in fact it is often explicitly repudiated” (1975: 134). Criticism of generalisability is of little relevance when the intention is one of particularisation. A second qualifier relates to the difference between statistical and analytical generalisation; single case studies are clearly less appropriate for the former but arguably retain significant utility for the latter – the difference also between explanatory and exploratory, or theory-testing and theory-building, as discussed above. As Gerring puts it, “theory confirmation/disconfirmation is not the case study’s strong suit” (2004: 350). A third qualification relates to the issue of case selection. As Seawright and Gerring (2008) note, the generalisability of case studies can be increased by the strategic selection of cases. Representative or random samples may not be the most appropriate, given that they may not provide the richest insight (or indeed, that a random and unknown deviant case may appear). Instead, and properly used , atypical or extreme cases “often reveal more information because they activate more actors… and more basic mechanisms in the situation studied” (Flyvbjerg, 2006). Of course, this also points to the very serious limitation, as hinted at with the case of India above, that poor case selection may alternatively lead to overgeneralisation and/or grievous misunderstandings of the relationship between variables or processes (Bennett and Elman, 2006a: 460-463).

As Tim May (2011: 226) notes, “the goal for many proponents of case studies […] is to overcome dichotomies between generalizing and particularizing, quantitative and qualitative, deductive and inductive techniques”. Research aims should drive methodological choices, rather than narrow and dogmatic preconceived approaches. As demonstrated above, there are various advantages to both idiographic and nomothetic single case study analyses – notably the empirically-rich, context-specific, holistic accounts that they have to offer, and their contribution to theory-building and, to a lesser extent, that of theory-testing. Furthermore, while they do possess clear limitations, any research method involves necessary trade-offs; the inherent weaknesses of any one method, however, can potentially be offset by situating them within a broader, pluralistic mixed-method research strategy. Whether or not single case studies are used in this fashion, they clearly have a great deal to offer.

References 

Bennett, A. and Checkel, J. T. (2012) ‘Process Tracing: From Philosophical Roots to Best Practice’, Simons Papers in Security and Development, No. 21/2012, School for International Studies, Simon Fraser University: Vancouver.

Bennett, A. and Elman, C. (2006a) ‘Qualitative Research: Recent Developments in Case Study Methods’, Annual Review of Political Science , 9, 455-476.

Bennett, A. and Elman, C. (2006b) ‘Complex Causal Relations and Case Study Methods: The Example of Path Dependence’, Political Analysis , 14, 3, 250-267.

Bennett, A. and Elman, C. (2007) ‘Case Study Methods in the International Relations Subfield’, Comparative Political Studies , 40, 2, 170-195.

Bennett, A. and Elman, C. (2010) Case Study Methods. In C. Reus-Smit and D. Snidal (eds) The Oxford Handbook of International Relations . Oxford University Press: Oxford. Ch. 29.

Berg, B. and Lune, H. (2012) Qualitative Research Methods for the Social Sciences . Pearson: London.

Bryman, A. (2012) Social Research Methods . Oxford University Press: Oxford.

David, M. and Sutton, C. D. (2011) Social Research: An Introduction . SAGE Publications Ltd: London.

Diamond, J. (1992) ‘Economic development and democracy reconsidered’, American Behavioral Scientist , 35, 4/5, 450-499.

Eckstein, H. (1975) Case Study and Theory in Political Science. In R. Gomm, M. Hammersley, and P. Foster (eds) Case Study Method . SAGE Publications Ltd: London.

Flyvbjerg, B. (2006) ‘Five Misunderstandings About Case-Study Research’, Qualitative Inquiry , 12, 2, 219-245.

Geertz, C. (1973) The Interpretation of Cultures: Selected Essays by Clifford Geertz . Basic Books Inc: New York.

Gerring, J. (2004) ‘What is a Case Study and What Is It Good for?’, American Political Science Review , 98, 2, 341-354.

Gerring, J. (2006a) Case Study Research: Principles and Practices . Cambridge University Press: Cambridge.

Gerring, J. (2006b) ‘Single-Outcome Studies: A Methodological Primer’, International Sociology , 21, 5, 707-734.

Gerring, J. (2007) ‘Is There a (Viable) Crucial-Case Method?’, Comparative Political Studies , 40, 3, 231-253.

King, G., Keohane, R. O. and Verba, S. (1994) Designing Social Inquiry: Scientific Inference in Qualitative Research . Princeton University Press: Chichester.

Layne, C. (1994) ‘Kant or Cant: The Myth of the Democratic Peace’, International Security , 19, 2, 5-49.

Levy, J. S. (2008) ‘Case Studies: Types, Designs, and Logics of Inference’, Conflict Management and Peace Science , 25, 1-18.

Lipset, S. M. (1959) ‘Some Social Requisites of Democracy: Economic Development and Political Legitimacy’, The American Political Science Review , 53, 1, 69-105.

Lyotard, J-F. (1984) The Postmodern Condition: A Report on Knowledge . University of Minnesota Press: Minneapolis.

MacMillan, A. (2008) ‘Deviant Democratization in India’, Democratization , 15, 4, 733-749.

Maoz, Z. (2002) Case study methodology in international studies: from storytelling to hypothesis testing. In F. P. Harvey and M. Brecher (eds) Evaluating Methodology in International Studies . University of Michigan Press: Ann Arbor.

May, T. (2011) Social Research: Issues, Methods and Process . Open University Press: Maidenhead.

Owen, J. M. (1994) ‘How Liberalism Produces Democratic Peace’, International Security , 19, 2, 87-125.

Seawright, J. and Gerring, J. (2008) ‘Case Selection Techniques in Case Study Research: A Menu of Qualitative and Quantitative Options’, Political Research Quarterly , 61, 2, 294-308.

Stake, R. E. (2008) Qualitative Case Studies. In N. K. Denzin and Y. S. Lincoln (eds) Strategies of Qualitative Inquiry . Sage Publications: Los Angeles. Ch. 17.

Van Evera, S. (1997) Guide to Methods for Students of Political Science . Cornell University Press: Ithaca.

Verschuren, P. J. M. (2003) ‘Case study as a research strategy: some ambiguities and opportunities’, International Journal of Social Research Methodology , 6, 2, 121-139.

Yin, R. K. (2009) Case Study Research: Design and Methods . SAGE Publications Ltd: London.

[1] The paper follows convention by differentiating between ‘International Relations’ as the academic discipline and ‘international relations’ as the subject of study.

[2] There is some similarity here with Stake’s (2008: 445-447) notion of intrinsic cases, those undertaken for a better understanding of the particular case, and instrumental ones that provide insight for the purposes of a wider external interest.

[3] These may be unique in the idiographic sense, or in nomothetic terms as an exception to the generalising suppositions of either probabilistic or deterministic theories (as per deviant cases, below).

[4] Although there are “philosophical hurdles to mount”, according to Bennett and Checkel, there exists no a priori reason as to why process tracing (as typically grounded in scientific realism) is fundamentally incompatible with various strands of positivism or interpretivism (2012: 18-19). By extension, it can therefore be incorporated by a range of contemporary mainstream IR theories.

— Written by: Ben Willis Written at: University of Plymouth Written for: David Brockington Date written: January 2013

Further Reading on E-International Relations

• Identity in International Conflicts: A Case Study of the Cuban Missile Crisis
• Imperialism’s Legacy in the Study of Contemporary Politics: The Case of Hegemonic Stability Theory
• Recreating a Nation’s Identity Through Symbolism: A Chinese Case Study
• Ontological Insecurity: A Case Study on Israeli-Palestinian Conflict in Jerusalem
• Terrorists or Freedom Fighters: A Case Study of ETA
• A Critical Assessment of Eco-Marxism: A Ghanaian Case Study

Please Consider Donating

Before you download your free e-book, please consider donating to support open access publishing.

E-IR is an independent non-profit publisher run by an all volunteer team. Your donations allow us to invest in new open access titles and pay our bandwidth bills to ensure we keep our existing titles free to view. Any amount, in any currency, is appreciated. Many thanks!

Donations are voluntary and not required to download the e-book - your link to download is below.

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

• View all journals
• Explore content
• About the journal
• Publish with us
• Sign up for alerts
• Perspective
• Published: 22 November 2022

Single case studies are a powerful tool for developing, testing and extending theories

• Lyndsey Nickels   ORCID: orcid.org/0000-0002-0311-3524 1 , 2 ,
• Simon Fischer-Baum   ORCID: orcid.org/0000-0002-6067-0538 3 &
• Wendy Best   ORCID: orcid.org/0000-0001-8375-5916 4  

Nature Reviews Psychology volume  1 ,  pages 733–747 ( 2022 ) Cite this article

627 Accesses

5 Citations

26 Altmetric

Metrics details

• Neurological disorders

Psychology embraces a diverse range of methodologies. However, most rely on averaging group data to draw conclusions. In this Perspective, we argue that single case methodology is a valuable tool for developing and extending psychological theories. We stress the importance of single case and case series research, drawing on classic and contemporary cases in which cognitive and perceptual deficits provide insights into typical cognitive processes in domains such as memory, delusions, reading and face perception. We unpack the key features of single case methodology, describe its strengths, its value in adjudicating between theories, and outline its benefits for a better understanding of deficits and hence more appropriate interventions. The unique insights that single case studies have provided illustrate the value of in-depth investigation within an individual. Single case methodology has an important place in the psychologist’s toolkit and it should be valued as a primary research tool.

This is a preview of subscription content, access via your institution

Access options

Subscribe to this journal

Receive 12 digital issues and online access to articles

55,14 € per year

only 4,60 € per issue

Rent or buy this article

Prices vary by article type

Prices may be subject to local taxes which are calculated during checkout

Similar content being viewed by others

Microdosing with psilocybin mushrooms: a double-blind placebo-controlled study

Federico Cavanna, Stephanie Muller, … Enzo Tagliazucchi

Adults who microdose psychedelics report health related motivations and lower levels of anxiety and depression compared to non-microdosers

Joseph M. Rootman, Pamela Kryskow, … Zach Walsh

Interviews in the social sciences

Eleanor Knott, Aliya Hamid Rao, … Chana Teeger

Corkin, S. Permanent Present Tense: The Unforgettable Life Of The Amnesic Patient, H. M . Vol. XIX, 364 (Basic Books, 2013).

Lilienfeld, S. O. Psychology: From Inquiry To Understanding (Pearson, 2019).

Schacter, D. L., Gilbert, D. T., Nock, M. K. & Wegner, D. M. Psychology (Worth Publishers, 2019).

Eysenck, M. W. & Brysbaert, M. Fundamentals Of Cognition (Routledge, 2018).

Squire, L. R. Memory and brain systems: 1969–2009. J. Neurosci. 29 , 12711–12716 (2009).

Article   PubMed   PubMed Central   Google Scholar  

Corkin, S. What’s new with the amnesic patient H.M.? Nat. Rev. Neurosci. 3 , 153–160 (2002).

Article   PubMed   Google Scholar  

Schubert, T. M. et al. Lack of awareness despite complex visual processing: evidence from event-related potentials in a case of selective metamorphopsia. Proc. Natl Acad. Sci. USA 117 , 16055–16064 (2020).

Behrmann, M. & Plaut, D. C. Bilateral hemispheric processing of words and faces: evidence from word impairments in prosopagnosia and face impairments in pure alexia. Cereb. Cortex 24 , 1102–1118 (2014).

Plaut, D. C. & Behrmann, M. Complementary neural representations for faces and words: a computational exploration. Cogn. Neuropsychol. 28 , 251–275 (2011).

Haxby, J. V. et al. Distributed and overlapping representations of faces and objects in ventral temporal cortex. Science 293 , 2425–2430 (2001).

Hirshorn, E. A. et al. Decoding and disrupting left midfusiform gyrus activity during word reading. Proc. Natl Acad. Sci. USA 113 , 8162–8167 (2016).

Kosakowski, H. L. et al. Selective responses to faces, scenes, and bodies in the ventral visual pathway of infants. Curr. Biol. 32 , 265–274.e5 (2022).

Harlow, J. Passage of an iron rod through the head. Boston Med. Surgical J . https://doi.org/10.1176/jnp.11.2.281 (1848).

Broca, P. Remarks on the seat of the faculty of articulated language, following an observation of aphemia (loss of speech). Bull. Soc. Anat. 6 , 330–357 (1861).

Google Scholar  

Dejerine, J. Contribution A L’étude Anatomo-pathologique Et Clinique Des Différentes Variétés De Cécité Verbale: I. Cécité Verbale Avec Agraphie Ou Troubles Très Marqués De L’écriture; II. Cécité Verbale Pure Avec Intégrité De L’écriture Spontanée Et Sous Dictée (Société de Biologie, 1892).

Liepmann, H. Das Krankheitsbild der Apraxie (“motorischen Asymbolie”) auf Grund eines Falles von einseitiger Apraxie (Fortsetzung). Eur. Neurol. 8 , 102–116 (1900).

Article   Google Scholar  

Basso, A., Spinnler, H., Vallar, G. & Zanobio, M. E. Left hemisphere damage and selective impairment of auditory verbal short-term memory. A case study. Neuropsychologia 20 , 263–274 (1982).

Humphreys, G. W. & Riddoch, M. J. The fractionation of visual agnosia. In Visual Object Processing: A Cognitive Neuropsychological Approach 281–306 (Lawrence Erlbaum, 1987).

Whitworth, A., Webster, J. & Howard, D. A Cognitive Neuropsychological Approach To Assessment And Intervention In Aphasia (Psychology Press, 2014).

Caramazza, A. On drawing inferences about the structure of normal cognitive systems from the analysis of patterns of impaired performance: the case for single-patient studies. Brain Cogn. 5 , 41–66 (1986).

Caramazza, A. & McCloskey, M. The case for single-patient studies. Cogn. Neuropsychol. 5 , 517–527 (1988).

Shallice, T. Cognitive neuropsychology and its vicissitudes: the fate of Caramazza’s axioms. Cogn. Neuropsychol. 32 , 385–411 (2015).

Shallice, T. From Neuropsychology To Mental Structure (Cambridge Univ. Press, 1988).

Coltheart, M. Assumptions and methods in cognitive neuropscyhology. In The Handbook Of Cognitive Neuropsychology: What Deficits Reveal About The Human Mind (ed. Rapp, B.) 3–22 (Psychology Press, 2001).

McCloskey, M. & Chaisilprungraung, T. The value of cognitive neuropsychology: the case of vision research. Cogn. Neuropsychol. 34 , 412–419 (2017).

McCloskey, M. The future of cognitive neuropsychology. In The Handbook Of Cognitive Neuropsychology: What Deficits Reveal About The Human Mind (ed. Rapp, B.) 593–610 (Psychology Press, 2001).

Lashley, K. S. In search of the engram. In Physiological Mechanisms in Animal Behavior 454–482 (Academic Press, 1950).

Squire, L. R. & Wixted, J. T. The cognitive neuroscience of human memory since H.M. Annu. Rev. Neurosci. 34 , 259–288 (2011).

Stone, G. O., Vanhoy, M. & Orden, G. C. V. Perception is a two-way street: feedforward and feedback phonology in visual word recognition. J. Mem. Lang. 36 , 337–359 (1997).

Perfetti, C. A. The psycholinguistics of spelling and reading. In Learning To Spell: Research, Theory, And Practice Across Languages 21–38 (Lawrence Erlbaum, 1997).

Nickels, L. The autocue? self-generated phonemic cues in the treatment of a disorder of reading and naming. Cogn. Neuropsychol. 9 , 155–182 (1992).

Rapp, B., Benzing, L. & Caramazza, A. The autonomy of lexical orthography. Cogn. Neuropsychol. 14 , 71–104 (1997).

Bonin, P., Roux, S. & Barry, C. Translating nonverbal pictures into verbal word names. Understanding lexical access and retrieval. In Past, Present, And Future Contributions Of Cognitive Writing Research To Cognitive Psychology 315–522 (Psychology Press, 2011).

Bonin, P., Fayol, M. & Gombert, J.-E. Role of phonological and orthographic codes in picture naming and writing: an interference paradigm study. Cah. Psychol. Cogn./Current Psychol. Cogn. 16 , 299–324 (1997).

Bonin, P., Fayol, M. & Peereman, R. Masked form priming in writing words from pictures: evidence for direct retrieval of orthographic codes. Acta Psychol. 99 , 311–328 (1998).

Bentin, S., Allison, T., Puce, A., Perez, E. & McCarthy, G. Electrophysiological studies of face perception in humans. J. Cogn. Neurosci. 8 , 551–565 (1996).

Jeffreys, D. A. Evoked potential studies of face and object processing. Vis. Cogn. 3 , 1–38 (1996).

Laganaro, M., Morand, S., Michel, C. M., Spinelli, L. & Schnider, A. ERP correlates of word production before and after stroke in an aphasic patient. J. Cogn. Neurosci. 23 , 374–381 (2011).

Indefrey, P. & Levelt, W. J. M. The spatial and temporal signatures of word production components. Cognition 92 , 101–144 (2004).

Valente, A., Burki, A. & Laganaro, M. ERP correlates of word production predictors in picture naming: a trial by trial multiple regression analysis from stimulus onset to response. Front. Neurosci. 8 , 390 (2014).

Kittredge, A. K., Dell, G. S., Verkuilen, J. & Schwartz, M. F. Where is the effect of frequency in word production? Insights from aphasic picture-naming errors. Cogn. Neuropsychol. 25 , 463–492 (2008).

Domdei, N. et al. Ultra-high contrast retinal display system for single photoreceptor psychophysics. Biomed. Opt. Express 9 , 157 (2018).

Poldrack, R. A. et al. Long-term neural and physiological phenotyping of a single human. Nat. Commun. 6 , 8885 (2015).

Coltheart, M. The assumptions of cognitive neuropsychology: reflections on Caramazza (1984, 1986). Cogn. Neuropsychol. 34 , 397–402 (2017).

Badecker, W. & Caramazza, A. A final brief in the case against agrammatism: the role of theory in the selection of data. Cognition 24 , 277–282 (1986).

Fischer-Baum, S. Making sense of deviance: Identifying dissociating cases within the case series approach. Cogn. Neuropsychol. 30 , 597–617 (2013).

Nickels, L., Howard, D. & Best, W. On the use of different methodologies in cognitive neuropsychology: drink deep and from several sources. Cogn. Neuropsychol. 28 , 475–485 (2011).

Dell, G. S. & Schwartz, M. F. Who’s in and who’s out? Inclusion criteria, model evaluation, and the treatment of exceptions in case series. Cogn. Neuropsychol. 28 , 515–520 (2011).

Schwartz, M. F. & Dell, G. S. Case series investigations in cognitive neuropsychology. Cogn. Neuropsychol. 27 , 477–494 (2010).

Cohen, J. A power primer. Psychol. Bull. 112 , 155–159 (1992).

Martin, R. C. & Allen, C. Case studies in neuropsychology. In APA Handbook Of Research Methods In Psychology Vol. 2 Research Designs: Quantitative, Qualitative, Neuropsychological, And Biological (eds Cooper, H. et al.) 633–646 (American Psychological Association, 2012).

Leivada, E., Westergaard, M., Duñabeitia, J. A. & Rothman, J. On the phantom-like appearance of bilingualism effects on neurocognition: (how) should we proceed? Bilingualism 24 , 197–210 (2021).

Arnett, J. J. The neglected 95%: why American psychology needs to become less American. Am. Psychol. 63 , 602–614 (2008).

Stolz, J. A., Besner, D. & Carr, T. H. Implications of measures of reliability for theories of priming: activity in semantic memory is inherently noisy and uncoordinated. Vis. Cogn. 12 , 284–336 (2005).

Cipora, K. et al. A minority pulls the sample mean: on the individual prevalence of robust group-level cognitive phenomena — the instance of the SNARC effect. Preprint at psyArXiv https://doi.org/10.31234/osf.io/bwyr3 (2019).

Andrews, S., Lo, S. & Xia, V. Individual differences in automatic semantic priming. J. Exp. Psychol. Hum. Percept. Perform. 43 , 1025–1039 (2017).

Tan, L. C. & Yap, M. J. Are individual differences in masked repetition and semantic priming reliable? Vis. Cogn. 24 , 182–200 (2016).

Olsson-Collentine, A., Wicherts, J. M. & van Assen, M. A. L. M. Heterogeneity in direct replications in psychology and its association with effect size. Psychol. Bull. 146 , 922–940 (2020).

Gratton, C. & Braga, R. M. Editorial overview: deep imaging of the individual brain: past, practice, and promise. Curr. Opin. Behav. Sci. 40 , iii–vi (2021).

Fedorenko, E. The early origins and the growing popularity of the individual-subject analytic approach in human neuroscience. Curr. Opin. Behav. Sci. 40 , 105–112 (2021).

Xue, A. et al. The detailed organization of the human cerebellum estimated by intrinsic functional connectivity within the individual. J. Neurophysiol. 125 , 358–384 (2021).

Petit, S. et al. Toward an individualized neural assessment of receptive language in children. J. Speech Lang. Hear. Res. 63 , 2361–2385 (2020).

Jung, K.-H. et al. Heterogeneity of cerebral white matter lesions and clinical correlates in older adults. Stroke 52 , 620–630 (2021).

Falcon, M. I., Jirsa, V. & Solodkin, A. A new neuroinformatics approach to personalized medicine in neurology: the virtual brain. Curr. Opin. Neurol. 29 , 429–436 (2016).

Duncan, G. J., Engel, M., Claessens, A. & Dowsett, C. J. Replication and robustness in developmental research. Dev. Psychol. 50 , 2417–2425 (2014).

Open Science Collaboration. Estimating the reproducibility of psychological science. Science 349 , aac4716 (2015).

Tackett, J. L., Brandes, C. M., King, K. M. & Markon, K. E. Psychology’s replication crisis and clinical psychological science. Annu. Rev. Clin. Psychol. 15 , 579–604 (2019).

Munafò, M. R. et al. A manifesto for reproducible science. Nat. Hum. Behav. 1 , 0021 (2017).

Oldfield, R. C. & Wingfield, A. The time it takes to name an object. Nature 202 , 1031–1032 (1964).

Oldfield, R. C. & Wingfield, A. Response latencies in naming objects. Q. J. Exp. Psychol. 17 , 273–281 (1965).

Brysbaert, M. How many participants do we have to include in properly powered experiments? A tutorial of power analysis with reference tables. J. Cogn. 2 , 16 (2019).

Brysbaert, M. Power considerations in bilingualism research: time to step up our game. Bilingualism https://doi.org/10.1017/S1366728920000437 (2020).

Machery, E. What is a replication? Phil. Sci. 87 , 545–567 (2020).

Nosek, B. A. & Errington, T. M. What is replication? PLoS Biol. 18 , e3000691 (2020).

Li, X., Huang, L., Yao, P. & Hyönä, J. Universal and specific reading mechanisms across different writing systems. Nat. Rev. Psychol. 1 , 133–144 (2022).

Rapp, B. (Ed.) The Handbook Of Cognitive Neuropsychology: What Deficits Reveal About The Human Mind (Psychology Press, 2001).

Code, C. et al. Classic Cases In Neuropsychology (Psychology Press, 1996).

Patterson, K., Marshall, J. C. & Coltheart, M. Surface Dyslexia: Neuropsychological And Cognitive Studies Of Phonological Reading (Routledge, 2017).

Marshall, J. C. & Newcombe, F. Patterns of paralexia: a psycholinguistic approach. J. Psycholinguist. Res. 2 , 175–199 (1973).

Castles, A. & Coltheart, M. Varieties of developmental dyslexia. Cognition 47 , 149–180 (1993).

Khentov-Kraus, L. & Friedmann, N. Vowel letter dyslexia. Cogn. Neuropsychol. 35 , 223–270 (2018).

Winskel, H. Orthographic and phonological parafoveal processing of consonants, vowels, and tones when reading Thai. Appl. Psycholinguist. 32 , 739–759 (2011).

Hepner, C., McCloskey, M. & Rapp, B. Do reading and spelling share orthographic representations? Evidence from developmental dysgraphia. Cogn. Neuropsychol. 34 , 119–143 (2017).

Hanley, J. R. & Sotiropoulos, A. Developmental surface dysgraphia without surface dyslexia. Cogn. Neuropsychol. 35 , 333–341 (2018).

Zihl, J. & Heywood, C. A. The contribution of single case studies to the neuroscience of vision: single case studies in vision neuroscience. Psych. J. 5 , 5–17 (2016).

Bouvier, S. E. & Engel, S. A. Behavioral deficits and cortical damage loci in cerebral achromatopsia. Cereb. Cortex 16 , 183–191 (2006).

Zihl, J. & Heywood, C. A. The contribution of LM to the neuroscience of movement vision. Front. Integr. Neurosci. 9 , 6 (2015).

Dotan, D. & Friedmann, N. Separate mechanisms for number reading and word reading: evidence from selective impairments. Cortex 114 , 176–192 (2019).

McCloskey, M. & Schubert, T. Shared versus separate processes for letter and digit identification. Cogn. Neuropsychol. 31 , 437–460 (2014).

Fayol, M. & Seron, X. On numerical representations. Insights from experimental, neuropsychological, and developmental research. In Handbook of Mathematical Cognition (ed. Campbell, J.) 3–23 (Psychological Press, 2005).

Bornstein, B. & Kidron, D. P. Prosopagnosia. J. Neurol. Neurosurg. Psychiat. 22 , 124–131 (1959).

Kühn, C. D., Gerlach, C., Andersen, K. B., Poulsen, M. & Starrfelt, R. Face recognition in developmental dyslexia: evidence for dissociation between faces and words. Cogn. Neuropsychol. 38 , 107–115 (2021).

Barton, J. J. S., Albonico, A., Susilo, T., Duchaine, B. & Corrow, S. L. Object recognition in acquired and developmental prosopagnosia. Cogn. Neuropsychol. 36 , 54–84 (2019).

Renault, B., Signoret, J.-L., Debruille, B., Breton, F. & Bolgert, F. Brain potentials reveal covert facial recognition in prosopagnosia. Neuropsychologia 27 , 905–912 (1989).

Bauer, R. M. Autonomic recognition of names and faces in prosopagnosia: a neuropsychological application of the guilty knowledge test. Neuropsychologia 22 , 457–469 (1984).

Haan, E. H. F., de, Young, A. & Newcombe, F. Face recognition without awareness. Cogn. Neuropsychol. 4 , 385–415 (1987).

Ellis, H. D. & Lewis, M. B. Capgras delusion: a window on face recognition. Trends Cogn. Sci. 5 , 149–156 (2001).

Ellis, H. D., Young, A. W., Quayle, A. H. & De Pauw, K. W. Reduced autonomic responses to faces in Capgras delusion. Proc. R. Soc. Lond. B 264 , 1085–1092 (1997).

Collins, M. N., Hawthorne, M. E., Gribbin, N. & Jacobson, R. Capgras’ syndrome with organic disorders. Postgrad. Med. J. 66 , 1064–1067 (1990).

Enoch, D., Puri, B. K. & Ball, H. Uncommon Psychiatric Syndromes 5th edn (Routledge, 2020).

Tranel, D., Damasio, H. & Damasio, A. R. Double dissociation between overt and covert face recognition. J. Cogn. Neurosci. 7 , 425–432 (1995).

Brighetti, G., Bonifacci, P., Borlimi, R. & Ottaviani, C. “Far from the heart far from the eye”: evidence from the Capgras delusion. Cogn. Neuropsychiat. 12 , 189–197 (2007).

Coltheart, M., Langdon, R. & McKay, R. Delusional belief. Annu. Rev. Psychol. 62 , 271–298 (2011).

Coltheart, M. Cognitive neuropsychiatry and delusional belief. Q. J. Exp. Psychol. 60 , 1041–1062 (2007).

Coltheart, M. & Davies, M. How unexpected observations lead to new beliefs: a Peircean pathway. Conscious. Cogn. 87 , 103037 (2021).

Coltheart, M. & Davies, M. Failure of hypothesis evaluation as a factor in delusional belief. Cogn. Neuropsychiat. 26 , 213–230 (2021).

McCloskey, M. et al. A developmental deficit in localizing objects from vision. Psychol. Sci. 6 , 112–117 (1995).

McCloskey, M., Valtonen, J. & Cohen Sherman, J. Representing orientation: a coordinate-system hypothesis and evidence from developmental deficits. Cogn. Neuropsychol. 23 , 680–713 (2006).

McCloskey, M. Spatial representations and multiple-visual-systems hypotheses: evidence from a developmental deficit in visual location and orientation processing. Cortex 40 , 677–694 (2004).

Gregory, E. & McCloskey, M. Mirror-image confusions: implications for representation and processing of object orientation. Cognition 116 , 110–129 (2010).

Gregory, E., Landau, B. & McCloskey, M. Representation of object orientation in children: evidence from mirror-image confusions. Vis. Cogn. 19 , 1035–1062 (2011).

Laine, M. & Martin, N. Cognitive neuropsychology has been, is, and will be significant to aphasiology. Aphasiology 26 , 1362–1376 (2012).

Howard, D. & Patterson, K. The Pyramids And Palm Trees Test: A Test Of Semantic Access From Words And Pictures (Thames Valley Test Co., 1992).

Kay, J., Lesser, R. & Coltheart, M. PALPA: Psycholinguistic Assessments Of Language Processing In Aphasia. 2: Picture & Word Semantics, Sentence Comprehension (Erlbaum, 2001).

Franklin, S. Dissociations in auditory word comprehension; evidence from nine fluent aphasic patients. Aphasiology 3 , 189–207 (1989).

Howard, D., Swinburn, K. & Porter, G. Putting the CAT out: what the comprehensive aphasia test has to offer. Aphasiology 24 , 56–74 (2010).

Conti-Ramsden, G., Crutchley, A. & Botting, N. The extent to which psychometric tests differentiate subgroups of children with SLI. J. Speech Lang. Hear. Res. 40 , 765–777 (1997).

Bishop, D. V. M. & McArthur, G. M. Individual differences in auditory processing in specific language impairment: a follow-up study using event-related potentials and behavioural thresholds. Cortex 41 , 327–341 (2005).

Bishop, D. V. M., Snowling, M. J., Thompson, P. A. & Greenhalgh, T., and the CATALISE-2 consortium. Phase 2 of CATALISE: a multinational and multidisciplinary Delphi consensus study of problems with language development: terminology. J. Child. Psychol. Psychiat. 58 , 1068–1080 (2017).

Wilson, A. J. et al. Principles underlying the design of ‘the number race’, an adaptive computer game for remediation of dyscalculia. Behav. Brain Funct. 2 , 19 (2006).

Basso, A. & Marangolo, P. Cognitive neuropsychological rehabilitation: the emperor’s new clothes? Neuropsychol. Rehabil. 10 , 219–229 (2000).

Murad, M. H., Asi, N., Alsawas, M. & Alahdab, F. New evidence pyramid. Evidence-based Med. 21 , 125–127 (2016).

Greenhalgh, T., Howick, J. & Maskrey, N., for the Evidence Based Medicine Renaissance Group. Evidence based medicine: a movement in crisis? Br. Med. J. 348 , g3725–g3725 (2014).

Best, W., Ping Sze, W., Edmundson, A. & Nickels, L. What counts as evidence? Swimming against the tide: valuing both clinically informed experimentally controlled case series and randomized controlled trials in intervention research. Evidence-based Commun. Assess. Interv. 13 , 107–135 (2019).

Best, W. et al. Understanding differing outcomes from semantic and phonological interventions with children with word-finding difficulties: a group and case series study. Cortex 134 , 145–161 (2021).

OCEBM Levels of Evidence Working Group. The Oxford Levels of Evidence 2. CEBM https://www.cebm.ox.ac.uk/resources/levels-of-evidence/ocebm-levels-of-evidence (2011).

Holler, D. E., Behrmann, M. & Snow, J. C. Real-world size coding of solid objects, but not 2-D or 3-D images, in visual agnosia patients with bilateral ventral lesions. Cortex 119 , 555–568 (2019).

Duchaine, B. C., Yovel, G., Butterworth, E. J. & Nakayama, K. Prosopagnosia as an impairment to face-specific mechanisms: elimination of the alternative hypotheses in a developmental case. Cogn. Neuropsychol. 23 , 714–747 (2006).

Hartley, T. et al. The hippocampus is required for short-term topographical memory in humans. Hippocampus 17 , 34–48 (2007).

Pishnamazi, M. et al. Attentional bias towards and away from fearful faces is modulated by developmental amygdala damage. Cortex 81 , 24–34 (2016).

Rapp, B., Fischer-Baum, S. & Miozzo, M. Modality and morphology: what we write may not be what we say. Psychol. Sci. 26 , 892–902 (2015).

Yong, K. X. X., Warren, J. D., Warrington, E. K. & Crutch, S. J. Intact reading in patients with profound early visual dysfunction. Cortex 49 , 2294–2306 (2013).

Rockland, K. S. & Van Hoesen, G. W. Direct temporal–occipital feedback connections to striate cortex (V1) in the macaque monkey. Cereb. Cortex 4 , 300–313 (1994).

Haynes, J.-D., Driver, J. & Rees, G. Visibility reflects dynamic changes of effective connectivity between V1 and fusiform cortex. Neuron 46 , 811–821 (2005).

Tanaka, K. Mechanisms of visual object recognition: monkey and human studies. Curr. Opin. Neurobiol. 7 , 523–529 (1997).

Fischer-Baum, S., McCloskey, M. & Rapp, B. Representation of letter position in spelling: evidence from acquired dysgraphia. Cognition 115 , 466–490 (2010).

Houghton, G. The problem of serial order: a neural network model of sequence learning and recall. In Current Research In Natural Language Generation (eds Dale, R., Mellish, C. & Zock, M.) 287–319 (Academic Press, 1990).

Fieder, N., Nickels, L., Biedermann, B. & Best, W. From “some butter” to “a butter”: an investigation of mass and count representation and processing. Cogn. Neuropsychol. 31 , 313–349 (2014).

Fieder, N., Nickels, L., Biedermann, B. & Best, W. How ‘some garlic’ becomes ‘a garlic’ or ‘some onion’: mass and count processing in aphasia. Neuropsychologia 75 , 626–645 (2015).

Schröder, A., Burchert, F. & Stadie, N. Training-induced improvement of noncanonical sentence production does not generalize to comprehension: evidence for modality-specific processes. Cogn. Neuropsychol. 32 , 195–220 (2015).

Stadie, N. et al. Unambiguous generalization effects after treatment of non-canonical sentence production in German agrammatism. Brain Lang. 104 , 211–229 (2008).

Schapiro, A. C., Gregory, E., Landau, B., McCloskey, M. & Turk-Browne, N. B. The necessity of the medial temporal lobe for statistical learning. J. Cogn. Neurosci. 26 , 1736–1747 (2014).

Schapiro, A. C., Kustner, L. V. & Turk-Browne, N. B. Shaping of object representations in the human medial temporal lobe based on temporal regularities. Curr. Biol. 22 , 1622–1627 (2012).

Baddeley, A., Vargha-Khadem, F. & Mishkin, M. Preserved recognition in a case of developmental amnesia: implications for the acaquisition of semantic memory? J. Cogn. Neurosci. 13 , 357–369 (2001).

Snyder, J. J. & Chatterjee, A. Spatial-temporal anisometries following right parietal damage. Neuropsychologia 42 , 1703–1708 (2004).

Ashkenazi, S., Henik, A., Ifergane, G. & Shelef, I. Basic numerical processing in left intraparietal sulcus (IPS) acalculia. Cortex 44 , 439–448 (2008).

Lebrun, M.-A., Moreau, P., McNally-Gagnon, A., Mignault Goulet, G. & Peretz, I. Congenital amusia in childhood: a case study. Cortex 48 , 683–688 (2012).

Vannuscorps, G., Andres, M. & Pillon, A. When does action comprehension need motor involvement? Evidence from upper limb aplasia. Cogn. Neuropsychol. 30 , 253–283 (2013).

Jeannerod, M. Neural simulation of action: a unifying mechanism for motor cognition. NeuroImage 14 , S103–S109 (2001).

Blakemore, S.-J. & Decety, J. From the perception of action to the understanding of intention. Nat. Rev. Neurosci. 2 , 561–567 (2001).

Rizzolatti, G. & Craighero, L. The mirror-neuron system. Annu. Rev. Neurosci. 27 , 169–192 (2004).

Forde, E. M. E., Humphreys, G. W. & Remoundou, M. Disordered knowledge of action order in action disorganisation syndrome. Neurocase 10 , 19–28 (2004).

Mazzi, C. & Savazzi, S. The glamor of old-style single-case studies in the neuroimaging era: insights from a patient with hemianopia. Front. Psychol. 10 , 965 (2019).

Coltheart, M. What has functional neuroimaging told us about the mind (so far)? (Position Paper Presented to the European Cognitive Neuropsychology Workshop, Bressanone, 2005). Cortex 42 , 323–331 (2006).

Page, M. P. A. What can’t functional neuroimaging tell the cognitive psychologist? Cortex 42 , 428–443 (2006).

Blank, I. A., Kiran, S. & Fedorenko, E. Can neuroimaging help aphasia researchers? Addressing generalizability, variability, and interpretability. Cogn. Neuropsychol. 34 , 377–393 (2017).

Niv, Y. The primacy of behavioral research for understanding the brain. Behav. Neurosci. 135 , 601–609 (2021).

Crawford, J. R. & Howell, D. C. Comparing an individual’s test score against norms derived from small samples. Clin. Neuropsychol. 12 , 482–486 (1998).

Crawford, J. R., Garthwaite, P. H. & Ryan, K. Comparing a single case to a control sample: testing for neuropsychological deficits and dissociations in the presence of covariates. Cortex 47 , 1166–1178 (2011).

McIntosh, R. D. & Rittmo, J. Ö. Power calculations in single-case neuropsychology: a practical primer. Cortex 135 , 146–158 (2021).

Patterson, K. & Plaut, D. C. “Shallow draughts intoxicate the brain”: lessons from cognitive science for cognitive neuropsychology. Top. Cogn. Sci. 1 , 39–58 (2009).

Lambon Ralph, M. A., Patterson, K. & Plaut, D. C. Finite case series or infinite single-case studies? Comments on “Case series investigations in cognitive neuropsychology” by Schwartz and Dell (2010). Cogn. Neuropsychol. 28 , 466–474 (2011).

Horien, C., Shen, X., Scheinost, D. & Constable, R. T. The individual functional connectome is unique and stable over months to years. NeuroImage 189 , 676–687 (2019).

Epelbaum, S. et al. Pure alexia as a disconnection syndrome: new diffusion imaging evidence for an old concept. Cortex 44 , 962–974 (2008).

Fischer-Baum, S. & Campana, G. Neuroplasticity and the logic of cognitive neuropsychology. Cogn. Neuropsychol. 34 , 403–411 (2017).

Paul, S., Baca, E. & Fischer-Baum, S. Cerebellar contributions to orthographic working memory: a single case cognitive neuropsychological investigation. Neuropsychologia 171 , 108242 (2022).

Feinstein, J. S., Adolphs, R., Damasio, A. & Tranel, D. The human amygdala and the induction and experience of fear. Curr. Biol. 21 , 34–38 (2011).

Crawford, J., Garthwaite, P. & Gray, C. Wanted: fully operational definitions of dissociations in single-case studies. Cortex 39 , 357–370 (2003).

McIntosh, R. D. Simple dissociations for a higher-powered neuropsychology. Cortex 103 , 256–265 (2018).

McIntosh, R. D. & Brooks, J. L. Current tests and trends in single-case neuropsychology. Cortex 47 , 1151–1159 (2011).

Best, W., Schröder, A. & Herbert, R. An investigation of a relative impairment in naming non-living items: theoretical and methodological implications. J. Neurolinguistics 19 , 96–123 (2006).

Franklin, S., Howard, D. & Patterson, K. Abstract word anomia. Cogn. Neuropsychol. 12 , 549–566 (1995).

Coltheart, M., Patterson, K. E. & Marshall, J. C. Deep Dyslexia (Routledge, 1980).

Nickels, L., Kohnen, S. & Biedermann, B. An untapped resource: treatment as a tool for revealing the nature of cognitive processes. Cogn. Neuropsychol. 27 , 539–562 (2010).

Download references

Acknowledgements

The authors thank all of those pioneers of and advocates for single case study research who have mentored, inspired and encouraged us over the years, and the many other colleagues with whom we have discussed these issues.

Author information

Authors and affiliations.

School of Psychological Sciences & Macquarie University Centre for Reading, Macquarie University, Sydney, New South Wales, Australia

Lyndsey Nickels

NHMRC Centre of Research Excellence in Aphasia Recovery and Rehabilitation, Australia

Psychological Sciences, Rice University, Houston, TX, USA

Simon Fischer-Baum

Psychology and Language Sciences, University College London, London, UK

You can also search for this author in PubMed   Google Scholar

Contributions

L.N. led and was primarily responsible for the structuring and writing of the manuscript. All authors contributed to all aspects of the article.

Corresponding author

Correspondence to Lyndsey Nickels .

Ethics declarations

Competing interests.

The authors declare no competing interests.

Peer review

Peer review information.

Nature Reviews Psychology thanks Yanchao Bi, Rob McIntosh, and the other, anonymous, reviewer for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Cite this article.

Nickels, L., Fischer-Baum, S. & Best, W. Single case studies are a powerful tool for developing, testing and extending theories. Nat Rev Psychol 1 , 733–747 (2022). https://doi.org/10.1038/s44159-022-00127-y

Download citation

Accepted : 13 October 2022

Published : 22 November 2022

Issue Date : December 2022

DOI : https://doi.org/10.1038/s44159-022-00127-y

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

Quick links

• Explore articles by subject
• Guide to authors
• Editorial policies

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

• CREd Library , Research Design and Method

Issues In Single-Subject Research

Kevin p kearns.

• March, 2011

DOI: 10.1044/cred-ssd-ps-cpri005

The following slides accompanied a presentation delivered at ASHA’s Clinical Practice Research Institute.

Data speak, not men…

“Designs have inherent rigor but not all studies using a design are rigorous” — Randy; yesterday

“Illusion of strong evidence…”– Gilbert, McPeek & Mosteller, 1977

Effects of Interpretation Bias on Research Evidence (Kaptchuk, 2003)

• “Good science inevitably embodies a tension between the empiricism of concrete data and the rationalism of deeply held convictions.”
• “…a view that science is totally objective is mythical and ignores the human element.”

Single-Subject Designs: Introduction

• Single subject experimental designs are among the most prevalent used in SLP treatment research. — (Kearns & Thompson, 1991; Thompson, 2006; Schlosser et al, 2004)
• Well designed single subject design studies are now commonly published in our journals as well as in interdisciplinary specialty journals — (Psychology, Neuropsychology, Education , PT, OT…)
• Agencies, including NIH, NIDDR etc., commonly fund conceptually salient and well designed single subject design treatment programs — (Aphasia, AAC, autism…)
• Meta-analyses have been employed to examine the overall impact of single subject studies on the efficacy and efficiency of interventions — (Robey et al., 1999)

• Quality indicators for single-subject designs appear to be less well understood than for group designs (Kratochwill & Stoiber, 2002; APA Div. 12; Horner, Carr, Halle, et al, 2005).
• Common threats to internal and external validity persist in our despite readily available solutions. (Schlosser, 2004; Thomson, 2006)

• Brief introduction to single subject designs
• Identify elements of single designs that contribute to problems with internal validity/experimental control from a reviewer’s perspective
• Discuss solutions for some of these issues; ultimately necessary for publication and external funding

Common Single-Subject Design Strategies

• Single-subject designs are experimental, not observational.
• Subjects “serve as their own controls”; receive both treatment and no-treatment conditions
• Juxtaposition of Baseline (A) phases with Treatment (B) phases provides mechanism for experimental control (internal validity)
• Control is based on within and across subject replication

Multiple- Baseline: Across Behaviors

Treatment vs No-treatment comparisons

• Examine efficacy of treatment relative to no treatment
• Multiple baselines/ variants; Withdrawal/ reversals

Component Assessment

• Relative contribution of treatment components
• Interaction Designs (variant of reversals)

Successive Level Analysis

• Examine successive levels of treatment
• Multiple Probe; Changing Criterion

Treatment – Treatment Comparisons

• Alternating Treatments (mixed m b )

ABAB Withdrawal Design

ATD-MB comparison: Broca’s aphasia

Internal Validity

• Operational specificity; reliability of IV, DV; treatment integrity; appropriate design
• Artifact, Bias
• Visual analysis of ‘control’: Loss of baseline (unstable; drifting trend); W/I and across phase changes: Level, Slope, Trend
• Replicated treatment effects: three demonstrations of the effect at three points in time

Visual-Graphic Analysis

• Level (on the ordinate; %..)
• Slope (stable, increasing, decreasing)
• Trend over time (variable; changes with phases; overlapping.)
• Overlap, immediacy of effect, similarity of effect for similar phases
• Correlation of change and phase change

Research on Visual Inspection of Single-Subject Data (Franklin et al, 1996; Robey et al, 1999)

• Low level of inter-rater agreement: De Prospero & Cohen (1979) Reported R = .61 among behavioral journal reviewers
• Reliability and validity of visual inspection can be improved with training (Hagopian et al, 1997)
• Visual aids (trend lines) may have produced only modest increase in reliability
• Traditional statistical analyses (eg. Binomial test) are highly affected by serial dependence (Crosbie, 1993)

Serial Dependence/Autocorrelation

• The level of behavior at one point in time is influenced by or correlated with the level of behavior at another point in time
• Autocorrelation biases interpretation and leads to Type I errors (falsely concluding a treatment effect exists; positive autocorrelation) and Type II errors (falsely concluding no treatment effect; negative autocorrelation)
• Independence assumption

• ITSACORR: A statistical procedure that controls for autocorrelation (Crosbie, 1993)
• Visual Inspection and Structured Criteria (Fisher, Kelley & Lomas, 2003; JABA)
• SMA bootstrapping approach (Borckardt, et al, 2008; AM Psychologist)
• clinicalresearcher.org

Baseline Measures

• Randomize order or stimulus sets/ conditions
• All treatment stimuli need to be assessed in baseline
• Establish equivalence for subsets of stimuli used as representative
• Avoid false baselines
• A priori stability decisions greatly reduce bias
• At least 7 baseline probes may be needed for reliable and valid visual analysis

S1 ITSACORR results were non-significant

S2 ITSACORR results were sig (F < .05)

Too few data points for valid analysis

Intervention

• Explicit steps; directions….a Manual
• Control for order effects
• Assess integrity of intervention (see Schlosser, 2004)
• One variable rule
• Is treatment intensity: sufficient; typical?
• Performance level (e.g. % correct)
• Maximum allowable length of treatment (but not equal phases)

Dependent Measures

• Use multiple measures
• Try not to collect during treatment sessions
• Probe often (weekly or more)
• Pre-train assistants the scoring code and periodically check for ‘drift’
• Are definitions specific, observable and replicable?

Reliability

• Reliability for both intervention and dependent variable
• Obtain for each phase of the study and adequately sample
• Control for sources of bias including drift and expectancy (ABCs — artifact, bias, and complexity)
• Use point to point reliability when possible
• Calculate probability of chance agreement; critical for periods of high or low responding
• Occurrence and non occurrence reliability

A priori Decisions

Failure to establish and make explicit criteria for guiding procedural and methodological decisions prior to change is a serious threat to internal validity that is difficult.

• Participant selection/ exclusion criteria (report attrition)
• Baseline variability, length
• Phase changes
• Clinical significance
• Generalization

Consider Clinically Meaningful Change

Clinical significance can not be assumed from our perspective alone.

Change in level of performance on any outcome measure, even when effects are large and visually obvious or significant, is an insufficient metric of the impact of experimental treatment on our participants/ patients.

Minimal Clinically Important Difference (MCID) : “the smallest difference in a score that is considered worthwhile or important” (Hays & Woolley, 2000)

Responsiveness of Health Measures (Husted et al., 2000) 1. Distribution based approaches examine internal responsiveness, using distribution/ variability of initial (baseline) scores to examine differences (e.g. Effect size).

2. Anchor based approaches examine external responsiveness by comparing change detected by a dependent measure with an external criterion. For example, specify a level of change that meets “minimal clinically important difference” (MCID).

Anchor-based Responsiveness measures (see Beninato, et al Archives of PMR, 2006) use external criterion as “anchor”

• Compare change score on outcome measure to some other estimate of important change
• Patient’s/Family estimates
• Clinician’s estimates
• Necessary to complete the EBP triangle?

Revisiting Clinically Important Change (Social Validation)

When the perceived change is important to the patient, clinician, researcher, payor or society (Beaton et al., 2001)

Requires that we extend our conceptual frame of reference beyond typical outcome measures and distribution based measures of responsiveness

“Time will tell” — (M. Planck, 1950)

“A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die.” — (Kaptchuk, 2003)

Franklin, R. D., Gorman, B. S., Beasley, T. M. & Allison, D. B. (1996). Graphical display and visual analysis.. Design and Snalysis of Single-Case Research , (pp. 119–158). Lawrence Erlbaum Associates.

Kearns, K. P. & Thompson, C. K. (1991). Technical drift and conceptual myopia: The Merlin effect. Clinical Aphasiology , 19, 31–40

Kevin P Kearns SUNY Fredonia

Presented at the Clinical Practice Research Institute (CPRI). Hosted by the American Speech-Language-Hearing Association Research Mentoring Network.

Copyrighted Material. Reproduced by the American Speech-Language-Hearing Association in the Clinical Research Education Library with permission from the author or presenter.

Clinical Research Education

More from the cred library, innovative treatments for persons with dementia, implementation science resources for crisp, when the ears interact with the brain, follow asha journals on twitter.

© 1997-2024 American Speech-Language-Hearing Association Privacy Notice Terms of Use

Have a language expert improve your writing

Run a free plagiarism check in 10 minutes, generate accurate citations for free.

• Knowledge Base

Methodology

• What Is a Case Study? | Definition, Examples & Methods

What Is a Case Study? | Definition, Examples & Methods

Published on May 8, 2019 by Shona McCombes . Revised on November 20, 2023.

A case study is a detailed study of a specific subject, such as a person, group, place, event, organization, or phenomenon. Case studies are commonly used in social, educational, clinical, and business research.

A case study research design usually involves qualitative methods , but quantitative methods are sometimes also used. Case studies are good for describing , comparing, evaluating and understanding different aspects of a research problem .

Table of contents

When to do a case study, step 1: select a case, step 2: build a theoretical framework, step 3: collect your data, step 4: describe and analyze the case, other interesting articles.

A case study is an appropriate research design when you want to gain concrete, contextual, in-depth knowledge about a specific real-world subject. It allows you to explore the key characteristics, meanings, and implications of the case.

Case studies are often a good choice in a thesis or dissertation . They keep your project focused and manageable when you don’t have the time or resources to do large-scale research.

You might use just one complex case study where you explore a single subject in depth, or conduct multiple case studies to compare and illuminate different aspects of your research problem.

Here's why students love Scribbr's proofreading services

Discover proofreading & editing

Once you have developed your problem statement and research questions , you should be ready to choose the specific case that you want to focus on. A good case study should have the potential to:

• Provide new or unexpected insights into the subject
• Challenge or complicate existing assumptions and theories
• Propose practical courses of action to resolve a problem
• Open up new directions for future research

TipIf your research is more practical in nature and aims to simultaneously investigate an issue as you solve it, consider conducting action research instead.

Unlike quantitative or experimental research , a strong case study does not require a random or representative sample. In fact, case studies often deliberately focus on unusual, neglected, or outlying cases which may shed new light on the research problem.

Example of an outlying case studyIn the 1960s the town of Roseto, Pennsylvania was discovered to have extremely low rates of heart disease compared to the US average. It became an important case study for understanding previously neglected causes of heart disease.

However, you can also choose a more common or representative case to exemplify a particular category, experience or phenomenon.

Example of a representative case studyIn the 1920s, two sociologists used Muncie, Indiana as a case study of a typical American city that supposedly exemplified the changing culture of the US at the time.

While case studies focus more on concrete details than general theories, they should usually have some connection with theory in the field. This way the case study is not just an isolated description, but is integrated into existing knowledge about the topic. It might aim to:

• Exemplify a theory by showing how it explains the case under investigation
• Expand on a theory by uncovering new concepts and ideas that need to be incorporated
• Challenge a theory by exploring an outlier case that doesn’t fit with established assumptions

To ensure that your analysis of the case has a solid academic grounding, you should conduct a literature review of sources related to the topic and develop a theoretical framework . This means identifying key concepts and theories to guide your analysis and interpretation.

There are many different research methods you can use to collect data on your subject. Case studies tend to focus on qualitative data using methods such as interviews , observations , and analysis of primary and secondary sources (e.g., newspaper articles, photographs, official records). Sometimes a case study will also collect quantitative data.

Example of a mixed methods case studyFor a case study of a wind farm development in a rural area, you could collect quantitative data on employment rates and business revenue, collect qualitative data on local people’s perceptions and experiences, and analyze local and national media coverage of the development.

The aim is to gain as thorough an understanding as possible of the case and its context.

Prevent plagiarism. Run a free check.

In writing up the case study, you need to bring together all the relevant aspects to give as complete a picture as possible of the subject.

How you report your findings depends on the type of research you are doing. Some case studies are structured like a standard scientific paper or thesis , with separate sections or chapters for the methods , results and discussion .

Others are written in a more narrative style, aiming to explore the case from various angles and analyze its meanings and implications (for example, by using textual analysis or discourse analysis ).

In all cases, though, make sure to give contextual details about the case, connect it back to the literature and theory, and discuss how it fits into wider patterns or debates.

If you want to know more about statistics , methodology , or research bias , make sure to check out some of our other articles with explanations and examples.

• Normal distribution
• Degrees of freedom
• Null hypothesis
• Discourse analysis
• Control groups
• Mixed methods research
• Non-probability sampling
• Quantitative research
• Ecological validity

Research bias

• Rosenthal effect
• Implicit bias
• Cognitive bias
• Selection bias
• Negativity bias
• Status quo bias

Cite this Scribbr article

If you want to cite this source, you can copy and paste the citation or click the “Cite this Scribbr article” button to automatically add the citation to our free Citation Generator.

McCombes, S. (2023, November 20). What Is a Case Study? | Definition, Examples & Methods. Scribbr. Retrieved April 1, 2024, from https://www.scribbr.com/methodology/case-study/

Is this article helpful?

Shona McCombes

Other students also liked, primary vs. secondary sources | difference & examples, what is a theoretical framework | guide to organizing, what is action research | definition & examples, what is your plagiarism score.

Case Study Research Method in Psychology

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.

Learn about our Editorial Process

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:

Case studies are in-depth investigations of a person, group, event, or community. Typically, data is gathered from various sources using several methods (e.g., observations & interviews).

The case study research method originated in clinical medicine (the case history, i.e., the patient’s personal history). In psychology, case studies are often confined to the study of a particular individual.

The information is mainly biographical and relates to events in the individual’s past (i.e., retrospective), as well as to significant events that are currently occurring in his or her everyday life.

The case study is not a research method, but researchers select methods of data collection and analysis that will generate material suitable for case studies.

Freud (1909a, 1909b) conducted very detailed investigations into the private lives of his patients in an attempt to both understand and help them overcome their illnesses.

This makes it clear that the case study is a method that should only be used by a psychologist, therapist, or psychiatrist, i.e., someone with a professional qualification.

There is an ethical issue of competence. Only someone qualified to diagnose and treat a person can conduct a formal case study relating to atypical (i.e., abnormal) behavior or atypical development.

 Famous Case Studies

• Anna O – One of the most famous case studies, documenting psychoanalyst Josef Breuer’s treatment of “Anna O” (real name Bertha Pappenheim) for hysteria in the late 1800s using early psychoanalytic theory.
• Little Hans – A child psychoanalysis case study published by Sigmund Freud in 1909 analyzing his five-year-old patient Herbert Graf’s house phobia as related to the Oedipus complex.
• Bruce/Brenda – Gender identity case of the boy (Bruce) whose botched circumcision led psychologist John Money to advise gender reassignment and raise him as a girl (Brenda) in the 1960s.
• Genie Wiley – Linguistics/psychological development case of the victim of extreme isolation abuse who was studied in 1970s California for effects of early language deprivation on acquiring speech later in life.
• Phineas Gage – One of the most famous neuropsychology case studies analyzes personality changes in railroad worker Phineas Gage after an 1848 brain injury involving a tamping iron piercing his skull.

Clinical Case Studies

• Studying the effectiveness of psychotherapy approaches with an individual patient
• Assessing and treating mental illnesses like depression, anxiety disorders, PTSD
• Neuropsychological cases investigating brain injuries or disorders

Child Psychology Case Studies

• Studying psychological development from birth through adolescence
• Cases of learning disabilities, autism spectrum disorders, ADHD
• Effects of trauma, abuse, deprivation on development

Types of Case Studies

• Explanatory case studies : Used to explore causation in order to find underlying principles. Helpful for doing qualitative analysis to explain presumed causal links.
• Exploratory case studies : Used to explore situations where an intervention being evaluated has no clear set of outcomes. It helps define questions and hypotheses for future research.
• Descriptive case studies : Describe an intervention or phenomenon and the real-life context in which it occurred. It is helpful for illustrating certain topics within an evaluation.
• Multiple-case studies : Used to explore differences between cases and replicate findings across cases. Helpful for comparing and contrasting specific cases.
• Intrinsic : Used to gain a better understanding of a particular case. Helpful for capturing the complexity of a single case.
• Collective : Used to explore a general phenomenon using multiple case studies. Helpful for jointly studying a group of cases in order to inquire into the phenomenon.

Where Do You Find Data for a Case Study?

There are several places to find data for a case study. The key is to gather data from multiple sources to get a complete picture of the case and corroborate facts or findings through triangulation of evidence. Most of this information is likely qualitative (i.e., verbal description rather than measurement), but the psychologist might also collect numerical data.

1. Primary sources

• Interviews – Interviewing key people related to the case to get their perspectives and insights. The interview is an extremely effective procedure for obtaining information about an individual, and it may be used to collect comments from the person’s friends, parents, employer, workmates, and others who have a good knowledge of the person, as well as to obtain facts from the person him or herself.
• Observations – Observing behaviors, interactions, processes, etc., related to the case as they unfold in real-time.
• Documents & Records – Reviewing private documents, diaries, public records, correspondence, meeting minutes, etc., relevant to the case.

2. Secondary sources

• News/Media – News coverage of events related to the case study.
• Academic articles – Journal articles, dissertations etc. that discuss the case.
• Government reports – Official data and records related to the case context.
• Books/films – Books, documentaries or films discussing the case.

3. Archival records

Searching historical archives, museum collections and databases to find relevant documents, visual/audio records related to the case history and context.

Public archives like newspapers, organizational records, photographic collections could all include potentially relevant pieces of information to shed light on attitudes, cultural perspectives, common practices and historical contexts related to psychology.

4. Organizational records

Organizational records offer the advantage of often having large datasets collected over time that can reveal or confirm psychological insights.

Of course, privacy and ethical concerns regarding confidential data must be navigated carefully.

However, with proper protocols, organizational records can provide invaluable context and empirical depth to qualitative case studies exploring the intersection of psychology and organizations.

• Organizational/industrial psychology research : Organizational records like employee surveys, turnover/retention data, policies, incident reports etc. may provide insight into topics like job satisfaction, workplace culture and dynamics, leadership issues, employee behaviors etc.
• Clinical psychology : Therapists/hospitals may grant access to anonymized medical records to study aspects like assessments, diagnoses, treatment plans etc. This could shed light on clinical practices.
• School psychology : Studies could utilize anonymized student records like test scores, grades, disciplinary issues, and counseling referrals to study child development, learning barriers, effectiveness of support programs, and more.

How do I Write a Case Study in Psychology?

Follow specified case study guidelines provided by a journal or your psychology tutor. General components of clinical case studies include: background, symptoms, assessments, diagnosis, treatment, and outcomes. Interpreting the information means the researcher decides what to include or leave out. A good case study should always clarify which information is the factual description and which is an inference or the researcher’s opinion.

1. Introduction

• Provide background on the case context and why it is of interest, presenting background information like demographics, relevant history, and presenting problem.
• Compare briefly to similar published cases if applicable. Clearly state the focus/importance of the case.

2. Case Presentation

• Describe the presenting problem in detail, including symptoms, duration,and impact on daily life.
• Include client demographics like age and gender, information about social relationships, and mental health history.
• Describe all physical, emotional, and/or sensory symptoms reported by the client.
• Use patient quotes to describe the initial complaint verbatim. Follow with full-sentence summaries of relevant history details gathered, including key components that led to a working diagnosis.
• Summarize clinical exam results, namely orthopedic/neurological tests, imaging, lab tests, etc. Note actual results rather than subjective conclusions. Provide images if clearly reproducible/anonymized.
• Clearly state the working diagnosis or clinical impression before transitioning to management.

3. Management and Outcome

• Indicate the total duration of care and number of treatments given over what timeframe. Use specific names/descriptions for any therapies/interventions applied.
• Present the results of the intervention,including any quantitative or qualitative data collected.
• For outcomes, utilize visual analog scales for pain, medication usage logs, etc., if possible. Include patient self-reports of improvement/worsening of symptoms. Note the reason for discharge/end of care.

4. Discussion

• Analyze the case, exploring contributing factors, limitations of the study, and connections to existing research.
• Analyze the effectiveness of the intervention,considering factors like participant adherence, limitations of the study, and potential alternative explanations for the results.
• Identify any questions raised in the case analysis and relate insights to established theories and current research if applicable. Avoid definitive claims about physiological explanations.
• Offer clinical implications, and suggest future research directions.

5. Additional Items

• Thank specific assistants for writing support only. No patient acknowledgments.
• References should directly support any key claims or quotes included.
• Use tables/figures/images only if substantially informative. Include permissions and legends/explanatory notes.
• Provides detailed (rich qualitative) information.
• Provides insight for further research.
• Permitting investigation of otherwise impractical (or unethical) situations.

Case studies allow a researcher to investigate a topic in far more detail than might be possible if they were trying to deal with a large number of research participants (nomothetic approach) with the aim of ‘averaging’.

Because of their in-depth, multi-sided approach, case studies often shed light on aspects of human thinking and behavior that would be unethical or impractical to study in other ways.

Research that only looks into the measurable aspects of human behavior is not likely to give us insights into the subjective dimension of experience, which is important to psychoanalytic and humanistic psychologists.

Case studies are often used in exploratory research. They can help us generate new ideas (that might be tested by other methods). They are an important way of illustrating theories and can help show how different aspects of a person’s life are related to each other.

The method is, therefore, important for psychologists who adopt a holistic point of view (i.e., humanistic psychologists ).

Limitations

• Lacking scientific rigor and providing little basis for generalization of results to the wider population.
• Researchers’ own subjective feelings may influence the case study (researcher bias).
• Difficult to replicate.
• Time-consuming and expensive.
• The volume of data, together with the time restrictions in place, impacted the depth of analysis that was possible within the available resources.

Because a case study deals with only one person/event/group, we can never be sure if the case study investigated is representative of the wider body of “similar” instances. This means the conclusions drawn from a particular case may not be transferable to other settings.

Because case studies are based on the analysis of qualitative (i.e., descriptive) data , a lot depends on the psychologist’s interpretation of the information she has acquired.

This means that there is a lot of scope for Anna O , and it could be that the subjective opinions of the psychologist intrude in the assessment of what the data means.

For example, Freud has been criticized for producing case studies in which the information was sometimes distorted to fit particular behavioral theories (e.g., Little Hans ).

This is also true of Money’s interpretation of the Bruce/Brenda case study (Diamond, 1997) when he ignored evidence that went against his theory.

Breuer, J., & Freud, S. (1895).  Studies on hysteria . Standard Edition 2: London.

Curtiss, S. (1981). Genie: The case of a modern wild child .

Diamond, M., & Sigmundson, K. (1997). Sex Reassignment at Birth: Long-term Review and Clinical Implications. Archives of Pediatrics & Adolescent Medicine , 151(3), 298-304

Freud, S. (1909a). Analysis of a phobia of a five year old boy. In The Pelican Freud Library (1977), Vol 8, Case Histories 1, pages 169-306

Freud, S. (1909b). Bemerkungen über einen Fall von Zwangsneurose (Der “Rattenmann”). Jb. psychoanal. psychopathol. Forsch ., I, p. 357-421; GW, VII, p. 379-463; Notes upon a case of obsessional neurosis, SE , 10: 151-318.

Harlow J. M. (1848). Passage of an iron rod through the head.  Boston Medical and Surgical Journal, 39 , 389–393.

Harlow, J. M. (1868).  Recovery from the Passage of an Iron Bar through the Head .  Publications of the Massachusetts Medical Society. 2  (3), 327-347.

Money, J., & Ehrhardt, A. A. (1972).  Man & Woman, Boy & Girl : The Differentiation and Dimorphism of Gender Identity from Conception to Maturity. Baltimore, Maryland: Johns Hopkins University Press.

Money, J., & Tucker, P. (1975). Sexual signatures: On being a man or a woman.

Further Information

• Case Study Approach
• Case Study Method
• Enhancing the Quality of Case Studies in Health Services Research
• “We do things together” A case study of “couplehood” in dementia
• Using mixed methods for evaluating an integrative approach to cancer care: a case study

• SUGGESTED TOPICS
• The Magazine
• Newsletters
• Managing Yourself
• Managing Teams
• Work-life Balance
• The Big Idea
• Data & Visuals
• Reading Lists
• Case Selections
• HBR Learning
• Topic Feeds
• Account Settings
• Email Preferences

Research: How Different Fields Are Using GenAI to Redefine Roles

• Maryam Alavi

Examples from customer support, management consulting, professional writing, legal analysis, and software and technology.

The interactive, conversational, analytical, and generative features of GenAI offer support for creativity, problem-solving, and processing and digestion of large bodies of information. Therefore, these features can act as cognitive resources for knowledge workers. Moreover, the capabilities of GenAI can mitigate various hindrances to effective performance that knowledge workers may encounter in their jobs, including time pressure, gaps in knowledge and skills, and negative feelings (such as boredom stemming from repetitive tasks or frustration arising from interactions with dissatisfied customers). Empirical research and field observations have already begun to reveal the value of GenAI capabilities and their potential for job crafting.

There is an expectation that implementing new and emerging Generative AI (GenAI) tools enhances the effectiveness and competitiveness of organizations. This belief is evidenced by current and planned investments in GenAI tools, especially by firms in knowledge-intensive industries such as finance, healthcare, and entertainment, among others. According to forecasts, enterprise spending on GenAI will increase by two-fold in 2024 and grow to $151.1 billion by 2027 .

• Maryam Alavi is the Elizabeth D. & Thomas M. Holder Chair & Professor of IT Management, Scheller College of Business, Georgia Institute of Technology .

Partner Center

• Search Menu
• Volume 2024, Issue 3, March 2024
• Bariatric Surgery
• Breast Surgery
• Cardiothoracic Surgery
• Colorectal Surgery
• Colorectal Surgery, Upper GI Surgery
• Gynaecology
• Hepatobiliary Surgery
• Interventional Radiology
• Neurosurgery
• Ophthalmology
• Oral and Maxillofacial Surgery
• Otorhinolaryngology - Head & Neck Surgery
• Paediatric Surgery
• Plastic Surgery
• Transplant Surgery
• Trauma & Orthopaedic Surgery
• Upper GI Surgery
• Vascular Surgery
• Author Guidelines
• Submission Site
• Open Access
• Reasons to Submit
• About Journal of Surgical Case Reports
• Editorial Board
• Advertising and Corporate Services
• Journals Career Network
• Self-Archiving Policy
• Journals on Oxford Academic
• Books on Oxford Academic

Article Contents

Introduction, author contributions, conflict of interest statement, ethical approval, informed consent.

• < Previous

Examining identical twins undergoing bariatric surgery: the single anastomosis duodeno–ileal bypass with sleeve gastrectomy (SADI-S) approach

• Article contents
• Figures & tables
• Supplementary Data

Rahul Menon, Philip Lockie, Examining identical twins undergoing bariatric surgery: the single anastomosis duodeno–ileal bypass with sleeve gastrectomy (SADI-S) approach, Journal of Surgical Case Reports , Volume 2024, Issue 3, March 2024, rjae192, https://doi.org/10.1093/jscr/rjae192

• Permissions Icon Permissions

Studies in monozygotic (MZ) twins may help researchers elucidate the complex relationships between genetic and environmental factors on weight loss. We present a world first of MZ twins who have undergone the single anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S) procedure who have identical weights 3 years post-operatively. Two MZ twin 49-year-old females were assessed preoperatively and were indicated for the SADI-S procedure. They underwent surgery in 2020 by the same surgical team. Three years later post-operatively they had identical weights of 62 kg (and a BMI of 23) and %EWL of 126 and 124% respectively. SADI-S is a novel bariatric procedure for morbid obesity. Studies have found concordant epigenetic patterns in patients who have undergone bariatric surgery as well as MZ twins who have hypocaloric diets. Genetics exert a strong influence in weight management. Surgical management as well as a collaborative multidisciplinary approach is beneficial in supporting long lasting weight loss in bariatric surgery.

In 2022, almost two thirds (65.8%) of adults in Australia were overweight or obese [ 1 ]. Over the last decade, the proportion of obese adults has increased and those with severe obesity are sitting at 13% [ 1 ]. When considering the effective management of long-term weight loss, lifestyle interventions, pharmacological interventions, and behavioural mechanisms are needed.

To further elucidate genetic as well as environmental influences on weight loss after bariatric surgery, we present the world’s first experience with monozygotic (MZ) twins using the single anastomosis duodenal-ileal bypass with sleeve gastrectomy (SADI-S) approach.

Case report

Two MZ twin females aged 49 were evaluated preoperatively by an identical multidisciplinary bariatric surgery team. Both patients had endoscopic placement of an intra-gastric balloon with minimal resultant weight loss. Preoperative weight for twin 1 was 93.2 kg (with a BMI of 35.1 kg/m 2 ) and twin 2 was 89 kg (with a BMI of 33.1 kg/m 2 ). Both twins had normal blood tests and no past medical history of note. The operation for both twins was completed a few weeks apart. In both patients, the abdomen was entered with a standard 12 mm port. Other ports were inserted under vision. The stomach was mobilized along the greater curvature with an energy device Harmonic Ace (Ethicon, Johnson&Johnson, NJ, USA). Sleeve gastrectomy was performed over a 38 Fr bougie and a 60 mm powered stapler device Echelon (Ethicon, Johnson&Johnson, NJ, USA). Resected stomach was removed and small bowel retrograde was measured at 300 cm for both patients. A loop duodeno-ileal anastomosis was created and the patient was closed in the normal fashion.

No complications were observed in either patient, and they were discharged in 48 h without any problems. The patients received regular nutritional, dietetic and psychological support throughout the post-operative period. At 3 years, both patients had identical weight of 62 kg (BMI of 23 kg/m 2 ) and %EWL of 126 and 124%, respectively.

We present the first report examining the changes in BMI and %EWL in MZ twins after a SADI-S procedure. At 3 years post-surgery, we observed several factors including psychological and social support as well as the importance of diet post-bariatric surgery. It is important to understand how complex interplays between genetics have a strong influence of weight management, which is supported by the extant literature [ 2 , 3 ].

The SADI-S is a novel and technically advanced hypo-absorptive bariatric procedures indicated for Class III obesity. Initially biliary diversion procedures were proposed by DeMeester et al., in 1987 as a suitable method for the duodenal inhibition of biliary reflux [ 4 ]. Other procedures only reduced symptoms partially and combined a significant complication rate [ 4–6 ]. Instead, a biliary diversion procedure with a single intestinal anastomosis was developed to prevent biliary reflux but also to prevent the potentially long-term and severe side effects associated [ 4 ].

Retrospective Study data have demonstrated that SADI-S has resulted in significant weight loss with a concurrent improvement in metabolic conditions like diabetes, dyslipidaemia, and obstructive sleep apnoea (OSA) [ 7–9 ]. A meta-analysis of 581 patients by Shoar et al. suggested an average excess weight loss percentage of 80% at 2 years [ 10 ]. Co-morbidity resolution rate was 74.1% for type 2 diabetes mellitus, 96.3% for hypertension, 68.3% for dyslipidaemia, 63.3% for OSA, and 87.5% for GORD [ 10 ]. SADI-S can be used both as a primary procedure, but also as a revision procedure when other bariatric procedures have failed or to stage subsequent procedures.

Genetic homozygosity in MZ twins helps us examine the complex interplay between genetic and environmental factors in the management of weight post-bariatric surgery. There is widespread controversy on the strength of genetic contribution to obesity and some researchers claim that they have a greater influence than environmental influences [ 11–13 ]. Concordance rates for degrees of obesity are twice as high for MZ twins as for dizygotic twins [ 14 ]. Adoption studies have examined genetic resemblance further with adoptees resembling the BMI of their biological parents and siblings but not of their adopted parents [ 15 ]. Stunkard et al. further compare the twins reared apart and together noting the intrapair correlation coefficients of twins reared apart closely resemble those of twins who are reared together [ 15 ]. These findings further corroborate earlier studies and suggest that genetic influences of BMI are substantial with environmental factors being less significant [ 15 ].

Epigenetic patterns in patients with obesity or concurrent metabolic disease have been observed in DNA analysis or blood samples from individuals with severe obesity [ 16 ]. Talukdar et al. have identified 41 significant epigenetic targets associated with weight loss due to bariatric surgery of which were also partially replicated in BMI-discordant MZ twins who followed a hypocaloric diet [ 16 ]. This suggests that bariatric surgery-induced weight loss improves both clinical and biochemical markers in health that are similarly seen in MZ twin studies regardless of the methods of weight loss [ 16 ]. Our own case study shows similar %EWL as well as similar improvements in metabolic markers suggesting that similar epigenetic changes could be observed in this cohort.

Morbidly obese patients are also afflicted with psychological comorbidities [ 17 ] and psychological support is integral in any bariatric programme. Frequent users of an online application based social support group post-bariatric surgery showed higher weight loss up to 2 years than compared with non-users [ 18 ], a meta-analysis examining this supports this further but boasts more modest results, with weight loss being similar at 6 months but being greater and remaining significant at 12 months [ 17 ]. Social support is an ideal platform to provide consistent psychological, emotional, and nutritional support throughout a bariatric programme and can promote a healthy lifestyle and prevent old habits from resurfacing [ 17 ].

The extant literature suggests that genetics exert a strong influence of obesity and the management of weight and metabolic conditions. Bariatric surgery in the morbidly obese remains the most effective method of lasting weight loss but post-operative social and psychological support are significant factors. MZ twins are ideal subjects to study genetic and environmental influences on weight loss, but further research will help identify which factors exert a more significant influence.

Literature review and drafting the manuscript: Rahul Menon. Philip Lockie provided guidance pertaining to the design and scope of the study. All authors have read and agreed to the published version of the manuscript.

None declared.

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

For all participants described in this study, full informed consent was sought.

Australian Bureau of Statistics . Waist circumference and BM . ABS ; 2022 . Available from: https://www.abs.gov.au/statistics/health/health-conditions-and-risks/waist-circumference-and-bmi/latest-release .

Hagedorn JC , Morton JM . Nature versus nurture: identical twins and bariatric surgery . Obes Surg 2007 ; 17 : 728 – 31 .

Google Scholar

Huseynov E , Coban G , Aliyev V . Laparoscopic sleeve gastrectomy in monozygotic twins: report of the first case . Cureus 2023 ; 15 : e35665 .

DeMeester TR , Fuchs KH , Ball CS , et al. . Experimental and clinical results with proximal end-to-end duodenojejunostomy for pathologic duodenogastric reflux . Ann Surg 1987 ; 206 : 414 – 26 .

Pellegrini CA , Patti MG , Lewin M , Way LW . Alkaline reflux gastritis and the effect of biliary diversion on gastric emptying of solid food . Am J Surg 1985 ; 150 : 166 – 71 .

Malagelada JR , Phillips SF , Shorter RG , et al. . Postoperative reflux gastritis: pathophysiology and long-term outcome after Roux-en-Y diversion . Ann Intern Med 1985 ; 103 : 178 – 83 .

Sánchez-Pernaute A , Herrera MAR , Pérez-Aguirre ME , et al. . Single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S). One to three-year follow-up . Obes Surg 2010 ; 20 : 1720 – 6 .

Torres A , Rubio MA , Ramos-Leví AM , Sánchez-Pernaute A . Cardiovascular risk factors after single anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S): a new effective therapeutic approach? Curr Atheroscler Rep 2017 ; 19 : 58 .

Surve A , Cottam D , Medlin W , et al. . Long-term outcomes of primary single-anastomosis duodeno-ileal bypass with sleeve gastrectomy (SADI-S) . Surg Obes Relat Dis Off J Am Soc Bariatr Surg 2020 ; 16 : 1638 – 46 .

Shoar S , Poliakin L , Rubenstein R , Saber AA . Single anastomosis duodeno-ileal switch (SADIS): a systematic review of efficacy and safety . Obes Surg 2018 ; 28 : 104 – 13 .

Grilo CM , Pogue-Geile MF . The nature of environmental influences on weight and obesity: a behavior genetic analysis . Psychol Bull 1991 ; 110 : 520 – 37 .

Hainer V , Stunkard A , Kunesová M , et al. . A twin study of weight loss and metabolic efficiency . Int J Obes Relat Metab Disord J Int Assoc Study Obes 2001 ; 25 : 533 – 7 .

Parmar CD , Bosch K , Benhmida R , et al. . First report of one anastomosis gastric bypass performed in twins . Obes Surg 2022 ; 32 : 1757 – 60 .

Stunkard AJ , Foch TT , Hrubec Z . A twin study of human obesity . JAMA 1986 ; 256 : 51 – 4 .

Stunkard AJ , Harris JR , Pedersen NL , McClearn GE . The body-mass index of twins who have been reared apart . N Engl J Med 1990 ; 322 : 1483 – 7 .

Talukdar FR , Escobar Marcillo DI , Laskar RS , et al. . Bariatric surgery-induced weight loss and associated genome-wide DNA-methylation alterations in obese individuals . Clin Epigenetics 2022 ; 14 : 176 .

Livhits M , Mercado C , Yermilov I , et al. . Is social support associated with greater weight loss after bariatric surgery?: a systematic review . Obes Rev Off J Int Assoc Study Obes 2011 ; 12 : 142 – 8 .

Athanasiadis DI , Carr RA , Smith C , et al. . Social support provided to bariatric surgery patients through a Facebook group may improve weight loss outcomes . Surg Endosc 2022 ; 36 : 7652 – 5 .

• body mass index procedure
• weight reduction
• ileal bypass
• anastomosis, surgical
• obesity, morbid
• surgical procedures, operative
• monozygotic twins
• bariatric surgery
• sleeve gastrectomy, laparoscopic

Email alerts

Citing articles via, affiliations.

• Online ISSN 2042-8812
• Copyright © 2024 Oxford University Press and JSCR Publishing Ltd
• About Oxford Academic
• Publish journals with us
• University press partners
• What we publish
• New features  
• Open access
• Institutional account management
• Rights and permissions
• Get help with access
• Accessibility
• Advertising
• Media enquiries
• Oxford University Press
• Oxford Languages
• University of Oxford

Oxford University Press is a department of the University of Oxford. It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide

• Copyright © 2024 Oxford University Press
• Cookie settings
• Cookie policy
• Privacy policy
• Legal notice

This Feature Is Available To Subscribers Only

Sign In or Create an Account

This PDF is available to Subscribers Only

For full access to this pdf, sign in to an existing account, or purchase an annual subscription.

• Share full article

For more audio journalism and storytelling, download New York Times Audio , a new iOS app available for news subscribers.

Hamas Took Her, and Still Has Her Husband

The story of one family at the center of the war in gaza..

This transcript was created using speech recognition software. While it has been reviewed by human transcribers, it may contain errors. Please review the episode audio before quoting from this transcript and email [email protected] with any questions.

I can’t remember the word, but do you know the kind of fungi connection between trees in the forest? How do you call it?

Mycelium. We are just — I just somehow feel that we are connected by this kind of infinite web of mycelium. We are so bound together. And I don’t think we really realized that until all this happened.

[MUSIC PLAYING]

It’s quite hard to explain, to me in a sense, because some people would say, oh, I’m so hoping your father will come, and then everything will be OK. And it’s very hard to explain that really this group of people decided to bring us up together, shared all their resources over 75 years, grow into each other, fight endlessly with each other, love and hate each other but somehow stay together. And their children will then meet and marry and make grandchildren.

And there’s so many levels of connection. And I’m sitting here in the room, and I see their faces, some of them. And we are incredibly — it’s hard to explain how much these people are missing from our kind of forest ground. [CHUCKLES SOFTLY]

From “The New York Times,” I’m Sabrina Tavernise, and this is “The Daily.”

It’s been nearly six months since Hamas attacked Israel on October 7 and took more than 200 people into Gaza. One of the hardest hit places was a village called Nir Oz, near the border with Gaza. One quarter of its residents were either killed or taken hostage.

Yocheved Lifshitz was one of those hostages and so was her husband, Oded Lifshitz. Yocheved was eventually released. Oded was not.

Today, the story of one family at the center of the war.

It’s Friday, March 29.

OK, here we go. OK.

Good morning, Yocheved. Good morning, Sharone.

Good morning.

Yocheved, could you identify yourself for me, please? Tell me your name, your age and where you’re from.

[SPEAKING HEBREW]

OK, I’ll translate. My name is Yocheved Lifshitz. I’m 85 years old. I was born in 1938. When I was 18, I arrived at kibbutz Nir Oz. I came alone with a group of people who decided to come and form and build a community on a very sandy territory, which was close to the Gaza Strip.

And my name is Sharone Lifschitz. I am 52 years old. I was raised in kibbutz Nir Oz by my mom and dad. So I lived there until I was 20. And I live for the last 30-something years in London.

And, Sharone, what do you have next to you?

Next to me I have a poster of my dad in both English and Hebrew. And it says, “Oded Lifshitz, 83.” And below that it says, “Bring him home now.” And it’s a photo where I always feel the love because he is looking at me. And there’s a lot of love in it in his eyes.

And why did you want to bring him here today, Sharone?

Because he should be talking himself. He should be here and able to tell his story. And instead, I’m doing it on his behalf. It should have been a story of my mom and dad sitting here and telling their story.

The story of Oded and Yocheved began before they ever met in Poland in the 1930s. Anti-Semitism was surging in Europe, and their families decided to flee to Palestine — Yocheved’s in 1933, the year Hitler came to power, and Oded’s a year later. Yocheved remembers a time near the end of the war, when her father received news from back home in Poland. He was deeply religious, a cantor in a synagogue. And he gathered his family around him to share what he’d learned.

And he said, we don’t have a family anymore. They’ve all been murdered. And he explained to us why there is no God. If there was a God, he would have protected my family. And this means that there is no God.

And suddenly, we stopped going to synagogue. We used to go every Saturday.

So it was a deep crisis for him. The shock and the trauma were very deep.

Abstention.

Abstention. Soviet Union? Yes. Yes. The United Kingdom? Abstained.

Yocheved’s father lived long enough to see a state establish for his children. The UN resolution of 1947 paved the way for a new country for Jews. And the next spring, Israel declared its independence. Yocheved remembers listening to the news on the radio with her parents.

The General Assembly of the United Nations has made its decision on Palestine.

We had a country. So now we’ll have somebody who’s protecting us. It’s a country for the people, to rebuild the people. This was the feeling we had.

In other words, if God could not protect you, this nation maybe could?

Yes. But the next day, it was already sad.

Israel was immediately forced to defend itself when its Arab neighbors attacked. Israel won that war. But its victory came at a great cost to the Palestinian Arabs living there. More than 700,000 either fled or were expelled from their homes. Many became refugees in Gaza in the south.

Suddenly, Yocheved and Oded saw themselves differently from their parents, not as minorities in someone else’s country, but as pioneers in a country of their own, ready to build it and defend it. They moved to the south, near the border line with Gaza. It was there, in a kibbutz, where they met for the first time.

The first time I met him, he was 16, and I was 17. And we didn’t really have this connection happening. But when we arrived at Nir Oz, that’s where some sort of a connection started to happen. And he was younger than I am by a year and a half. So at first I thought, he’s a kid. But for some reason, he insisted. Oded really insisted. And later, turned out he was right.

What was it about him that made you fall in love with him?

He was cute.

He was a cute kid. He was a cute boy.

What’s so funny?

He was a philosopher. He wrote a lot. He worked in agriculture. He was this cute boy. He was only 20, think about it.

And then I married him. And he brought two things with him. He brought a dog and he brought a cactus. And since then we’ve been growing a huge field of cacti for over 64 years.

What did it feel like to be starting a new life together in this new country? What was the feeling of that?

We were euphoric.

And what did you think you were building together?

We thought we were building a kibbutz. We were building a family. We were having babies. That was the vision. And we were thinking that we were building a socialist state, an equal state. And at first, it was a very isolated place. There were only two houses and shacks and a lot of sand. And little by little, we turned that place into a heaven.

Building the new state meant cultivating the land. Oded plowed the fields, planting potatoes and carrots, wheat and cotton. Yocheved was in charge of the turkeys and worked in the kitchen cooking meals for the kibbutz. They believed that the best way to live was communally. So they shared everything — money, food, even child-rearing.

After long days in the fields, Oded would venture outside the kibbutz to the boundary line with Gaza and drink beer with Brazilian peacekeepers from the UN and talk with Palestinians from the villages nearby. They talked about politics and life in Arabic, a language Oded spoke fluently. These were not just idle conversations. Oded knew that for Israel to succeed, it would have to figure out how to live side by side with its Arab neighbors.

He really did not believe in black and white, that somebody is the bad guy and somebody is the good guy, but there is a humanistic values that you can live in.

Sharone, what was your father like?

My father was a tall man and a skinny man. And he was —

he is — first of all, he is — he is a man who had very strong opinion and very well formed opinion. He read extensively. He thought deeply about matters. And he studied the piano. But as he said, was never that great or fast enough for classical. But he always played the piano.

[PIANO MUSIC]

He would play a lot of Israeli songs. He wound play Russian songs. He would play French chansons.

And he had this way of just moving from one song to the next, making it into a kind of pattern. And it was — it’s really the soundtrack of our life, my father playing the piano.

[PLAYING PIANO]:

[CONVERSATION IN HEBREW]:

[PLAYING PIANO]

So one side of him was the piano. Another side was he was a peace activist. He was not somebody who just had ideals about building bridges between nations. He was always on the left side of the political map, and he actioned it.

[NON-ENGLISH CHANTING]:

I remember growing up and going very regularly, almost weekly, to demonstrations. I will go regularly with my father on Saturday night to demonstrations in Tel Aviv. I will sit on his shoulders. He will be talking to all his activist friends. The smoke will rise from the cigarettes, and I will sit up there.

But somehow, we really grew up in that fight for peace.

Yocheved and Oded’s formal fight for peace began after the Arab-Israeli war of 1967. Israel had captured new territory, including the West Bank, the Sinai Peninsula, and the Gaza Strip. That brought more than a million Palestinians under Israeli occupation.

Oded immediately began to speak against it. Israel already had its land inside borders that much of the world had agreed to. In his view, taking more was wrong. It was no longer about Jewish survival. So when Israeli authorities began quietly pushing Bedouin Arabs off their land in the Sinai Peninsula, Oded took up the cause.

He helped file a case in the Israeli courts to try to stop it. And he and Yocheved worked together to draw attention to what was going on. Yocheved was a photographer, so she took pictures showing destroyed buildings and bulldozed land. Oded then put her photographs on cardboard and drove around the country showing them to people everywhere.

They became part of a growing peace movement that was becoming a force helping shape Israeli politics. Israel eventually returned the Sinai Peninsula to Egypt in 1982.

[NON-ENGLISH SPEECH]

Whenever there is a movement towards reconciliation with our neighbors, it’s almost like your ability to live here, your life force, gets stronger. And in a way, you can think of the art of their activism as being a response to that.

And why did he and your mother take up that fight, the cause of the land? Why do you think that was what he fought for?

My father, he had a very developed sense of justice. And he always felt that had we returned those lands at that point, we could have reached long-term agreement at that point. Then we would have been in a very different space now. I know that in 2019, for example, he wrote a column, where he said that when the Palestinians of Gaza have nothing to lose, we lose big time. He believed that the way of living in this part of the world is to share the place, to reach agreement, to work with the other side towards agreements.

He was not somebody who just had ideals about building bridges between nations. Two weeks before he was taken hostage, he still drove Palestinians that are ill to reach hospital in Israel and in East Jerusalem. That was something that meant a lot to him. I think he really believed in shared humanity and in doing what you can.

Do you remember the last conversation you had with your father?

I don’t have a clear memory which one it was. It’s funny. A lot of things I forgot since. A lot of things have gone so blurred.

We actually didn’t have a last conversation. The last thing he said was, Yoche, there is a war. And he was shot in the hand, and he was taken out. And I was taken out. I couldn’t say goodbye to him. And what was done to us was done.

We’ll be right back.

Yocheved, the last thing Oded said was there’s a war. Tell me about what happened that day from the beginning.

That morning, there was very heavy shelling on Nir Oz. We could hear gunfire. And we looked outside, and Oded told me, there are a lot of terrorists outside. We didn’t even have time to get dressed. I was still wearing my nightgown. He was wearing very few clothes. I remember him trying to close the door to the safe room, but it didn’t work. He wasn’t successful in closing it.

And then five terrorists walked in. They shot him through the safe room door. He was bleeding from his arm. He said to me, Yoche, I’m injured. And then he fainted. He was dragged out on the floor. And I didn’t know if he was alive. I thought he was dead. After that, I was taken in my nightgown. I was led outside. I was placed on a small moped, and I was taken to Gaza.

And we were driving over a bumpy terrain that had been plowed. And it didn’t break my ribs, but it was very painful.

And I could see that the gate that surrounds the Gaza Strip was broken, and we were driving right through it.

And as we were heading in, I could see so many people they were yelling, “Yitbach al Yahud,” kill the Jews, slaughter the Jews. And people were hitting me with sticks. And though the drivers on the moped tried to protect me, it didn’t help.

What were you thinking at the time? What was in your mind?

I was thinking, I’m being taken; I’m being kidnapped. I didn’t know where to, but this decision I had in my head was that I’m going to take photographs in my mind and capture everything I’m seeing so that when I — or if and when I am released, I’ll have what to tell.

And when I came to a stop, we were in a village that’s near Nir Oz. It’s called Khirbet Khuza. We came in on the moped, but I was transferred into a private car from there. And I was threatened that my hand would be cut off unless I hand over my watch and my ring. And I didn’t have a choice, so I took my watch off, and I took my ring off, and I handed it to them.

Was it your wedding ring?

Yes, it was my wedding ring.

After that, they led me to a big hangar where the entrance to the tunnel was, and I started walking. And the entrance was at ground level, but as you walk, you’re walking down a slope. And you’re walking and walking about 40 meters deep underground, and the walls are damp, and the soil is damp. And at first, I was alone. I didn’t know that other people had been taken too. But then more hostages came, and we were walking together through the tunnels.

Many of whom were from kibbutz Nir Oz. These were our people. They were abducted but still alive. And we spoke quietly, and we spoke very little. But as we were walking, everybody started telling a story of what had happened to him. And that created a very painful picture.

There were appalling stories about murder. People had left behind a partner.

A friend arrived, who, about an hour or two hours before, had her husband murdered and he died in her hands.

It was a collection of broken up people brought together.

So you were piecing together the story of your community and what had happened from these snapshots of tragedies that you were looking at all around you as you were walking. What’s the photograph you’ll remember most from that day?

It would be a girl, a four-year-old girl. People kept telling her — walk, walk, walk. And we tried to calm her down. And her mom tried to carry her on her arms. It was the most difficult sight to see a child inside those tunnels.

What were you feeling at that moment, Yocheved?

Very difficult.

Where did they lead you — you and your community — from Nir Oz.

They led us to this chamber, a room, that they had prepared in advance. There were mattresses there. And that’s where we were told to sit.

I saw people sitting on the mattresses, bent down, their heads down between their hands. They were broken. But we hardly spoke. Everybody was inside their own world with themselves, closed inside his own personal shock.

Yocheved was without her glasses, her hearing aids, or even her shoes. She said she spent most days lying down on one of the mattresses that had been put out for the hostages. Sometimes her captors would let her and others walk up and down the tunnels to stretch their legs.

She said she was given a cucumber, spreading cheese, and a piece of pita bread every day to eat. They had a little bit of coffee in the morning and water all day long.

One day, a Hamas leader came to the room where she and others were being held. She said she believes it was Yahya Sinwar, the leader of Hamas, who is believed to be the architect of the October 7 attack. Two other hostages who were held with Yocheved also identified the man as Sinwar, and an Israeli military spokesman said he found the accounts reliable.

He came accompanied with a group of other men. He just made rounds between the hostages, I suppose. And he spoke in Hebrew, and he told us not to worry, and soon there’s going to be a deal and we’ll be out. And others told me, don’t speak. And I said, what is there for me to be afraid of? The worst already happened. Worst thing, I’ll be killed.

I want to say something, and I spoke my mind. I told Sinwar, why have you done what you just did to all of the same people who have always helped you? He didn’t answer me. He just turned around and they walked off.

Were you afraid to ask him why Hamas did what it did, to challenge him?

I wasn’t afraid.

I was angry about the whole situation. It was against every thought and thinking we ever had. It was against our desire to reach peace, to be attentive and help our neighbors the way we always wanted to help our neighbors. I was very angry. But he ignored what I said, and he just turned his back and walked away.

In this entire time, you had no answers about Oded?

What was the hardest day for you, the hardest moment in captivity?

It’s when I got sick. I got sick with diarrhea and vomiting for about four days. And I had no idea how this will end. It was a few very rough days. And probably because of that, they decided to free me.

They didn’t tell me they were going to release me. They just told me and another girl, come follow us. They gave us galabiya gowns to wear and scarves to wear over our heads, so maybe they’ll think that we are Arab women. And only as we were walking, and we started going through corridors and ladders and climbing up we were told that we’re going home.

I was very happy to be going out. But my heart ached so hard for those who were staying behind. I was hoping that many others would follow me.

It’s OK. Let’s go. It’s OK. Let’s go.

You go with this one.

Shalom. Shalom.

There was a video that was made of the moment you left your captors. And it seemed to show that you were shaking a hand, saying shalom to them. Do you remember doing that?

I said goodbye to him. It was a friendly man. He was a medic. So when we said goodbye, I shook his hand for peace, shalom, to goodbye.

What did you mean when you said that?

I meant for peace.

Shalom in the sense of peace.

An extraordinary moment as a freed Israeli hostage shakes hands with a Hamas terrorist who held her captive.

I literally saw my mom on CNN on my phone on the way to the airport. And it was the day before I was talking to my aunt, and she said, I just want to go to Gaza and pull them out of the earth. I just want to pull them out of the earth and take them. And it really felt like that, that she came out of the earth. And when she shook the hand of the Hamas person, it just made me smile because it was so her to see the human in that person and to acknowledge him as a human being.

I arrived in the hospital at about 5:30 AM. My mom was asleep in the bed. And she was just — my mom sleeps really peacefully. She has a really quiet way of sleeping. And I just sat there, and it was just like a miracle to have her back with us. It was just incredible because not only was she back, but it was her.

I don’t know how to explain it. But while they were away, we knew so little. We were pretty sure she didn’t survive it. The whole house burned down totally. So other homes we could see if there was blood on the walls or blood on the floor. But in my parents’ home, everything was gone — everything. And we just didn’t know anything. And out of that nothingness, came my mom back.

It was only when she got to the hospital that Yocheved learned the full story of what happened on October 7. Nir Oz had been mostly destroyed. Many of her friends had been murdered. No one knew what had happened to Oded. Yocheved believed he was dead. But there wasn’t time to grieve.

The photograph she had taken in her mind needed to be shared. Yocheved knew who was still alive in the tunnels. So she and her son called as many families as they could — the family of the kibbutz’s history teacher, of one of its nurses, of the person who ran its art gallery — to tell them that they were still alive, captive in Gaza.

And then in November came a hostage release. More than 100 people came out. The family was certain that Oded was gone. But Sharone decided to make some calls anyway. She spoke to one former neighbor then another. And finally, almost by chance, she found someone who’d seen her father. They shared a room together in Gaza before he’d gotten ill and was taken away. Sharone and her brothers went to where Yocheved was staying to tell her the news.

She just couldn’t believe it, actually. It was as if, in this great telenovela of our life, at one season, he was left unconscious on the floor. And the second season open, and he is in a little room in Gaza with another woman that we know. She couldn’t believe it.

She was very, very, very excited, also really worried. My father was a very active and strong man. And if it happened 10 years ago, I would say of course he would survive it. He would talk to them in Arabic. He will manage the situation. He would have agency. But we know he was injured. And it makes us very, very worried about the condition in which he was — he’s surviving there. And I think that the fear of how much suffering the hostages are going through really makes you unable to function at moment.

Yocheved, the government has been doing a military operation since October in Gaza. You have been fighting very hard since October to free the hostages, including Oded. I wonder how you see the government’s military operation. Is it something that harms your cause or potentially helps it?

The only thing that will bring them back are agreements. And what is happening is that there are many soldiers who have been killed, and there is an ongoing war, and the hostages are still in captivity. So it’s only by reaching an agreement that all of the hostages will be released.

Do you believe that Israel is close to reaching an agreement?

I don’t know.

You told us that after the Holocaust, your father gathered your family together to tell you that God did not save you. It was a crisis for him. I’m wondering if this experience, October 7, your captivity, challenged your faith in a similar way.

No, I don’t think it changed me. I’m still the same person with the same beliefs and opinions. But how should I say it? What the Hamas did was to ruin a certain belief in human beings. I didn’t think that one could reach that level that isn’t that much higher than a beast. But my opinion and my view of there still being peace and reaching an arrangement stayed the same.

You still believe in peace?

Why do you believe that?

Because I’m hoping that a new generation of leaders will rise, people who act in transparency, who speak the truth, people who are honest, the way Israel used to be and that we’ll return to be like we once were.

I go to many rallies and demonstrations, and I meet many people in many places. And a large part of those people still believe in reaching an arrangement in peace and for there to be no war. And I still hope that this is what we’re going to be able to have here.

Bring them home now! Bring them home now! Bring them home now! Bring them home now! Bring them home! Now! Bring them home! Now! Bring them home! Now! Bring them home!

Yocheved is now living in a retirement home in the suburbs of Tel Aviv. Five other people around her age from Nir Oz live there too. One is also a released hostage. She hasn’t been able to bring herself to go back to the kibbutz. The life she built there with Oded is gone — her photographs, his records, the piano. And the kibbutz has become something else now, a symbol instead of a home. It is now buzzing with journalists and politicians. For now, Yocheved doesn’t know if she’ll ever go back. And when Sharone asked her, she said, let’s wait for Dad.

So I’m today sitting in this assisted living, surrounded by the same company, just expecting Oded, waiting for Oded to come back. And then each and every one of us will be rebuilding his own life together and renewing it.

What are you doing to make it a home for Oded?

We have a piano. We were given a piano, a very old one with a beautiful sound. And it’s good. Oded is very sensitive to the sound. He has absolute hearing. And I’m just hoping for him to come home and start playing the piano.

Do you believe that Oded will come home?

I’d like to believe. But there’s a difference between believing and wanting. I want to believe that he’ll be back and playing music. I don’t think his opinions are going to change. He’s going to be disappointed by what happened. But I hope he’s going to hold on to the same beliefs. His music is missing from our home.

[SPEAKING HEBEW]:

[SPEAKING HEBREW] [PLAYING PIANO]

I know that my father always felt that we haven’t given peace a chance. That was his opinion. And I think it’s very hard to speak for my father because maybe he has changed. Like my mom said, she said, I hope he hasn’t changed. I haven’t changed. But the truth is we don’t know. And we don’t the story. We don’t know how the story — my father is ending or just beginning.

But I think you have to hold on to humanistic values at this point. You have to know what you don’t want. I don’t want more of this. This is hell. This is hell for everybody. So this is no, you know? And then I believe that peace is also gray, and it’s not glorious, and it’s not simple. It’s kind of a lot of hard work. You have to reconcile and give up a lot. And it’s only worth doing that for peace.

[PIANO PLAYING CONTINUES]

After weeks of negotiations, talks over another hostage release and ceasefire have reached an impasse. The sticking points include the length of the ceasefire and the identity and number of Palestinian prisoners to be exchanged for the hostages.

[BACKGROUND CONVERSATION IN HEBREW]:

Here’s what else you should know today. Sam Bankman-Fried was sentenced to 25 years in prison on Thursday, capping an extraordinary saga that upended the multi-trillion-dollar crypto industry. Bankman-Fried, the founder of the cryptocurrency exchange, FTX, was convicted of wire fraud, conspiracy, and money laundering last November.

Prosecutors accused him of stealing more than $10 billion from customers to finance political contributions, venture capital investments, and other extravagant purchases. At the sentencing, the judge pointed to testimony from Bankman-Fried’s trial, saying that his appetite for extreme risk and failure to take responsibility for his crimes amount to a quote, “risk that this man will be in a position to do something very bad in the future.”

Today’s episode was produced by Lynsea Garrison and Mooj Zaidie with help from Rikki Novetsky and Shannon Lin. It was edited by Michael Benoist, fact checked by Susan Lee, contains original music by Marion Lozano, Dan Powell, Diane Wong, Elisheba Ittoop, and Oded Lifshitz. It was engineered by Alyssa Moxley. The translation was by Gabby Sobelman. Special thanks to Menachem Rosenberg, Gershom Gorenberg, Gabby Sobelman, Yotam Shabtie, and Patrick Kingsley. Our theme music is by Jim Brunberg and Ben Landsverk of Wonderly.

That’s it for “The Daily.” I’m Sabrina Tavernise. See you on Monday.

• April 1, 2024   •   36:14 Ronna McDaniel, TV News and the Trump Problem
• March 29, 2024   •   48:42 Hamas Took Her, and Still Has Her Husband
• March 28, 2024   •   33:40 The Newest Tech Start-Up Billionaire? Donald Trump.
• March 27, 2024   •   28:06 Democrats’ Plan to Save the Republican House Speaker
• March 26, 2024   •   29:13 The United States vs. the iPhone
• March 25, 2024   •   25:59 A Terrorist Attack in Russia
• March 24, 2024   •   21:39 The Sunday Read: ‘My Goldendoodle Spent a Week at Some Luxury Dog ‘Hotels.’ I Tagged Along.’
• March 22, 2024   •   35:30 Chuck Schumer on His Campaign to Oust Israel’s Leader
• March 21, 2024   •   27:18 The Caitlin Clark Phenomenon
• March 20, 2024   •   25:58 The Bombshell Case That Will Transform the Housing Market
• March 19, 2024   •   27:29 Trump’s Plan to Take Away Biden’s Biggest Advantage
• March 18, 2024   •   23:18 Your Car May Be Spying on You

Hosted by Sabrina Tavernise

Produced by Lynsea Garrison and Mooj Zadie

With Rikki Novetsky and Shannon Lin

Edited by Michael Benoist

Original music by Marion Lozano ,  Dan Powell ,  Diane Wong and Elisheba Ittoop

Engineered by Alyssa Moxley

Listen and follow The Daily Apple Podcasts | Spotify | Amazon Music

Warning: this episode contains descriptions of violence.

It’s been nearly six months since the Hamas-led attacks on Israel, when militants took more than 200 hostages into Gaza.

In a village called Nir Oz, near the border, one quarter of residents were either killed or taken hostage. Yocheved Lifshitz and her husband, Oded Lifshitz, were among those taken.

Today, Yocheved and her daughter Sharone tell their story.

On today’s episode

Yocheved Lifshitz, a former hostage.

Sharone Lifschitz, daughter of Yocheved and Oded Lifshitz.

Background reading

Yocheved Lifshitz was beaten and held in tunnels built by Hamas for 17 days.

There are a lot of ways to listen to The Daily. Here’s how.

We aim to make transcripts available the next workday after an episode’s publication. You can find them at the top of the page.

Fact-checking by Susan Lee .

Additional music by Oded Lifshitz.

Translations by Gabby Sobelman .

Special thanks to Menachem Rosenberg, Gershom Gorenberg , Gabby Sobelman , Yotam Shabtie, and Patrick Kingsley .

The Daily is made by Rachel Quester, Lynsea Garrison, Clare Toeniskoetter, Paige Cowett, Michael Simon Johnson, Brad Fisher, Chris Wood, Jessica Cheung, Stella Tan, Alexandra Leigh Young, Lisa Chow, Eric Krupke, Marc Georges, Luke Vander Ploeg, M.J. Davis Lin, Dan Powell, Sydney Harper, Mike Benoist, Liz O. Baylen, Asthaa Chaturvedi, Rachelle Bonja, Diana Nguyen, Marion Lozano, Corey Schreppel, Rob Szypko, Elisheba Ittoop, Mooj Zadie, Patricia Willens, Rowan Niemisto, Jody Becker, Rikki Novetsky, John Ketchum, Nina Feldman, Will Reid, Carlos Prieto, Ben Calhoun, Susan Lee, Lexie Diao, Mary Wilson, Alex Stern, Dan Farrell, Sophia Lanman, Shannon Lin, Diane Wong, Devon Taylor, Alyssa Moxley, Summer Thomad, Olivia Natt, Daniel Ramirez and Brendan Klinkenberg.

Our theme music is by Jim Brunberg and Ben Landsverk of Wonderly. Special thanks to Sam Dolnick, Paula Szuchman, Lisa Tobin, Larissa Anderson, Julia Simon, Sofia Milan, Mahima Chablani, Elizabeth Davis-Moorer, Jeffrey Miranda, Renan Borelli, Maddy Masiello, Isabella Anderson and Nina Lassam.

Advertisement

An official website of the United States government

The .gov means it’s official. Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

The site is secure. The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

• Publications
• Account settings

Preview improvements coming to the PMC website in October 2024. Learn More or Try it out now .

• Advanced Search
• Journal List
• HHS Author Manuscripts
• PMC10016625

The Family of Single-Case Experimental Designs

Leonard h. epstein.

1 Jacobs School of Medicine and Biomedical Sciences, Division of Behavioral Medicine, Department of Pediatrics, University at Buffalo, Buffalo, New York, United States of America,

Jesse Dallery

2 Department of Psychology, University of Florida, Gainesville, Florida, United States of America

Single-case experimental designs (SCEDs) represent a family of research designs that use experimental methods to study the effects of treatments on outcomes. The fundamental unit of analysis is the single case—which can be an individual, clinic, or community—ideally with replications of effects within and/or between cases. These designs are flexible and cost-effective and can be used for treatment development, translational research, personalized interventions, and the study of rare diseases and disorders. This article provides a broad overview of the family of single-case experimental designs with corresponding examples, including reversal designs, multiple baseline designs, combined multiple baseline/reversal designs, and integration of single-case designs to identify optimal treatments for individuals into larger randomized controlled trials (RCTs). Personalized N-of-1 trials can be considered a subcategory of SCEDs that overlaps with reversal designs. Relevant issues for each type of design—including comparisons of treatments, design issues such as randomization and blinding, standards for designs, and statistical approaches to complement visual inspection of single-case experimental designs—are also discussed.

1. Introduction

Single-case experimental designs (SCEDs) represent a family of experimental designs to examine the relationship between one or more treatments or levels of treatment and changes in biological or behavioral outcomes. These designs originated in early experimental psychology research ( Boring, 1929 ; Ebbinghaus, 1913 ; Pavlov, 1927 ), and were later expanded and formalized in the fields of basic and applied behavior analysis ( Morgan & Morgan, 2001 ; Sidman, 1960 ). SCEDs have been extended to a number of fields, including medicine ( Lillie et al., 2011 ; Schork, 2015 ), public health ( Biglan et al., 2000 ; Duan et al., 2013 ), education ( Horner et al., 2005 ), counseling psychology ( Lundervold & Belwood, 2000 ), clinical psychology ( Vlaeyen et al., 2020 ), health behavior ( McDonald et al., 2017 ), and neuroscience ( Soto, 2020 ).

SCEDs provide a framework to determine whether changes in a target behavior(s) or symptom are in fact a function of the intervention. The fundamentals of an SCED involve repeated measurement, replication of conditions (e.g., baseline and intervention conditions), and the analysis of effects with respect to each individual serving as his or her own control. This process can be useful for identifying the optimal treatment for an individual ( Dallery & Raiff, 2014 ; Davidson et al., 2021 ), treating rare diseases ( Abrahamyan et al., 2016 ), and implementing early phase translational research ( Czajkowski et al., 2015 ). SCEDs can be referred to as ‘personalized (N-of-1) trials’ when used this way, but they also have broad applicability to a range of scientific questions. Results from SCEDs can be aggregated using meta-analytic techniques to establish generalizable methods and treatment guidelines ( Shadish, 2014 ; Vannest et al., 2018 ). Figure 1 presents the main family of SCEDs, and shows how personalized (N-of-1) trials fit into these designs ( Vohra et al., 2016 ). The figure also distinguishes between experimental and nonexperimental single-case designs. In the current article, we provide an overview of SCEDs and thus a context for the articles in this special issue focused on personalized (N-of-1) trials. Our focus is to provide the fundamentals of these designs, and more detailed treatments of data analysis ( Moeyaert & Fingerhut, 2022 ; Schork, 2022 ) conduct and reporting standards ( Kravitz & Duan, 2022 ; Porcino & Vohra, 2022 ), and other methodological considerations are provided in this special issue. Our hope is that this article will inspire a diverse array of students, engineers, scientists, and practitioners to further explore the utility, rigor, and flexibility of these designs.

A = Baseline, B and C refer to different treatments.

The most common approach to evaluating the effectiveness of interventions on outcomes is using randomized controlled trials (RCTs). RCTs provide an idea of the average effect of an intervention on outcomes. People do not all change at the same rate or in the same way, however; variability in both how people change and the effect of the intervention is inevitable ( Fisher et al., 2018 ; Normand, 2016 ; Roustit et al., 2018 ). These sources of variability are conflated in a typical RCT, leading to heterogeneity of treatment effects (HTE). Research on HTE has shown variability in outcomes in RCTs, and in some studies very few people actually exhibit the benefits of that treatment ( Williams, 2010 ). One approach in RCTs is to assess moderators of treatment response to identify individual differences that may predict response to a treatment. This approach may not limit variability in response, and substantial reduction in variability of treatment for subgroups in comparison to the group as a whole is far from assured. Even if variability is reduced, the average effect for that subgroup may not be representative of individual members of the subgroup.

SCEDs can identify the optimal treatment for an individual person rather than the average person in a group ( Dallery & Raiff, 2014 ; Davidson et al., 2021 ; Hekler et al., 2020 ). SCEDs are multiphase experimental designs in which a great deal of data is collected on a single person, said person serves as his or her own control ( Kazdin, 2011 , 2021 ), and the order of presentation of conditions can be randomized to enhance experimental control. That is, a person’s outcomes in one phase are compared to outcomes in another phase. In a typical study, replications are achieved within and/or across several individuals; this allows for strong inferences about causation between behavior and the treatment (or levels thereof). Achieving replications is synonymous with achieving experimental control.

We provide an overview of three experimental designs that can be adapted for personalized medicine: reversal, multiple baseline, and combined reversal and multiple baseline designs, and we discuss how SCEDs can be integrated into RCTs. These designs focus on demonstrating experimental control of the relationship between treatment and outcome. Several general principles common to all of the designs are noteworthy ( Lobo et al., 2017 ). First, in many studies, treatment effects are compared with control conditions with a no- intervention baseline as the initial condition. To reduce threats to internal validity of the study, the order of assignment of interventions can be randomized ( Kratochwill & Levin, 2010 ) and, when possible, the intervention and data collection can be blinded. The demonstration of experimental control across conditions or people needs to be replicated several times (three replications is the minimum) to ensure confidence of the relationship between treatment and outcome ( Kratochwill et al., 2010 ; Kratochwill & Levin, 2015 ). Demonstrating stability of data within a phase or, otherwise, no trend in the direction of treatment effects prior to starting treatment is particularly important. Stability refers to the degree of variability in the data path over time (e.g., data points must fall within a 15% range of the median for a condition). Thus, phase length needs to be flexible for the sake of determining stability and trend within a phase, but a minimum of 5 data points per phase has been recommended ( Kratochwill et al., 2013 ). The focus of the intervention’s effects is on clinically rather than statistically significant effects with the target effect prespecified and considered in interpretation of the relevance of the effect for clinical practice ( Epstein et al., 2021 ). In addition, multiple dependent outcomes can be simultaneously measured ( Epstein et al., 2021 ). SCEDs can be used to test whether a variable mediates the effect of a treatment on symptoms or behavior ( Miočević et al., 2020 ; Riley & Gaynor, 2014 ). Visual inspection of graphical data is typically used to determine treatment effects, and statistical methods are commonly used to assist in interpretation of graphical data ( Epstein et al., 2021 ). Furthermore, a growing number of statistical approaches can summarize treatment effects and provide effect sizes ( Kazdin, 2021 ; Moeyaert & Fingerhut, this issue; Pustejovsky, 2019 ; Shadish et al., 2014 ). Data across many SCED trials can be aggregated to assess the generality of the treatment effects to help address for whom and under what conditions an intervention is effective ( Branch & Pennypacker, 2013 ; Shadish, 2014 ; Van den Noortgate & Onghena, 2003 ).

2. Reversal Designs

A reversal design collects behavioral or biological outcome data in at least two phases: a baseline or no treatment phase (labeled as ‘A’) and the experimental or treatment phase (labeled as ‘B’). The design is called a reversal design because there must be reversals or replications of phases for each individual; for example, in an ABA design, the baseline phase is replicated ( Kazdin, 2011 ). Ideally, three replications of treatment effects are used to demonstrate experimental control ( Kratochwill et al., 2010 ; Kratochwill & Levin, 1992 ). Figure 2 shows hypothetical results from an A1B1A2B2 design. The graph shows three replications of treatment effects (A1 versus B1, B1 versus A2, A2 versus B2) across four participants. Each phase was carried out until stability was evident from visual inspection of the data as well as absence of trends in the direction of the desired effect. The replication across participants increases the confidence in the effectiveness of the intervention. Extension of this design is possible by comparing multiple interventions, as well. The order of the treatments should be randomized, especially when the goal is to combine SCEDs across participants.

A1 = First Baseline, B1 First Treatment, A2 = Return to Baseline, B2 = Return to Treatment. P1–P4 represent different hypothetical participants.

Reversal designs can be more dynamic and compare several treatments. A common approach in personalized medicine would be to compare two or more doses of or different components of the same treatment ( Ward-Horner & Sturmey, 2010 ). For example, two drug doses could be compared using an A1B1C1B2C2 design, where A represents placebo and B and C represent the different drug doses ( Guyatt et al., 1990 ). In the case of drug studies, the drug/placebo administration can be double blinded. A more complex design could be A1B1A2C1A3C2A4B2, which would yield multiple replications of the comparison between drug and placebo. Based on the kinetics of the drug and the need for a washout period, the design could also be A1B1C1B2C2. This would provide three demonstration of treatment effects: B1 to C1, C1 to B2, and B2 to C2. Other permutations could be planned strategically to identify the optimal dose for each individual.

Advantages of SCED reversal designs are their ability to experimentally show that a particular treatment was functionally related to a particular change in an outcome variable for that person . This is the core principle of personalized medicine: an optimal treatment for an individual can be identified ( Dallery & Raiff, 2014 ; Davidson et al., 2021 ; Guyatt et al., 1990 ; Hekler et al., 2020 ; Lillie et al., 2011 ). These designs can work well for studying the effect of interventions on rare diseases in which collecting enough participants with similar characteristics for an RCT would be unlikely. An additional strength is the opportunity for the clinical researcher who also delivers clinical care to translate basic science findings or new findings from RCTs to their patients, who can potentially benefit ( Dallery & Raiff, 2014 ; Hayes, 1981 ). Research suggests that the trickledown of new developments and hypotheses to their support in RCTs can take more than 15 years; many important advancements in the medical and behavior sciences are likely not to be implemented rapidly enough ( Riley et al., 2013 ). The ability to test new intervention developments using scientific principles could speed up their translation into practice.

Limitations to SCED designs, however, are worth noting. Firstly, in line with the expectation that the outcome returns to baseline levels, reversals may require removal of the treatment. If the effect is not quickly reversible, then the designs are not relevant. A washout period may be placed in-between phases if the effect is not immediately reversible; for example, a drug washout period could be planned based on the half-life of drug. Secondly, the intervention should have a relatively immediate effect on the outcome. If many weeks to months are needed for some interventions to show effects, a reversal design may not be optimal unless the investigator is willing to plan a lengthy study. Thirdly, the design depends on comparing stable data over conditions. If achieving stability due to uncontrolled sources of biological or environmental variation is not possible, a reversal design may not be appropriate to evaluate a treatment, though it may be useful to identify the sources of variability ( Sidman, 1960 ). Finally, for a reversal to a baseline, a no-treatment phase may be inappropriate in investigating treatment effects for a very ill patient.

3. Multiple Baseline Designs

An alternative to a reversal design is the multiple baseline design, which does not require reversal of conditions to establish experimental control. There are three types of multiple baseline designs: multiple baseline across people, behaviors, and settings. The most popular is the multiple baseline across people, in which baselines are established for three or more people for the same outcome ( Cushing et al., 2011 ; Meredith et al., 2011 ). Treatment is implemented after different durations of baseline across individuals. The order of treatment implementation across people can be randomized ( Wen et al., 2019 ). Figure 3 shows an example across three individuals. In this hypothetical example, baseline data for each person are relatively stable and not decreasing, and reductions in the dependent variable are only observed after introduction of the intervention. Inclusion of one control person, who remains in baseline throughout the study and provides a control for extended monitoring, is also possible. Another variation is to collect baseline data intermittently in a ‘probe’ design, which can minimize burden associated with simultaneous and repeated measurement of outcomes ( Byiers et al., 2012 ; Horner & Baer, 1978 ). If the outcomes do not change during baseline conditions and the changes only occur across participants after the treatment has been implemented—and this sequence is replicated across several people—change in the outcome may be safely attributed to the treatment. The length of the baselines still must be long enough to show stability and no trend toward improvement until the treatment is implemented.

P1–P3 represent different hypothetical participants.

The two other multiple baseline designs focus on individual people: the multiple baseline across settings and the multiple baseline across behaviors ( Boles et al., 2008 ; Lane-Brown & Tate, 2010 ). An example of a multiple baseline across settings would be a dietary intervention implemented across meals. An intervention that targets a reduction in consumption of high–glycemic index foods, or foods with added sugar across meals, could be developed with the order of meals randomized. For example, someone may be randomized to reduce sugar-added or high–glycemic index foods for breakfast without any implementation at lunch or dinner. Implementation of the diet at lunch and then dinner would occur after different durations of baselines in these settings. An example of multiple baseline across behaviors might be to use feedback to develop a comprehensive exercise program that involves stretching, aerobic exercise, and resistance training. Feedback could target improvement in one of these randomly selected behaviors, implemented in a staggered manner.

The main limitation to a multiple baseline design is that some people (or behaviors) may be kept in baseline or control conditions for extended periods before treatment is implemented. Of course, failure to receive an effective treatment is common in RCTs for people who are randomized to control conditions, but unlike control groups in RCTs, all participants eventually receive treatment.

Finally, while the emphasis in personalized medicine is the identification of an optimal treatment plan for an individual person, situations in which multiple baselines across people prove relevant for precision medicine may arise. For example, identification of a small group of people with common characteristics—perhaps with a rare disease and for which a multiple-baseline-across-people design could be used to test an intervention more effectively than a series of personalized designs—is possible. In a similar vein, differential response to a common treatment in a multiple-baseline-across-people design can help to identify individual differences that can compromise the response to a treatment.

4. Integrating Multiple Baseline and Reversal Designs

While reversal designs can be used to compare effects of interventions, multiple baseline designs provide experimental control for testing one intervention but do not compare different interventions. One way to take advantage of the strengths of both designs is to combine them. For example, the effects of a first treatment could be studied using a multiple-baseline format and, after experimental control has been established, return to baseline prior to the commencement of a different treatment, which may be introduced in a different order. These comparisons can be made for several different interventions with the combination of both designs to demonstrate experimental control and compare effects of the interventions.

Figure 4 shows a hypothetical example of a combined approach to identify the best drug to decrease blood pressure. Baseline blood pressures are established for three people under placebo conditions before new drug X is introduced across participants in a staggered fashion to establish relative changes in blood pressure. All return to placebo after blood pressures reach stability, drug Y is introduced in a staggered sequence, participants are returned to placebo, and the most effective intervention for each individual (drug X or Y) is reintroduced to replicate the most important result: the most effective medication. This across-subjects design establishes experimental control for two different new drug interventions across three people while also establishing experimental control for five comparisons within subjects (placebo—drug X, drug Y—placebo, placebo—drug Y, drug Y—placebo, placebo—more effective drug). Though this combined design strengthens confidence beyond either reversal or multiple baseline designs, in many situations, experimental control demonstrated using a reversal design is sufficient.

BL = Baseline. Drug X and Drug Y represent hypothetical drugs to lower blood pressure, and Best Drug represents a reversal to the most effective drug as identified for each hypothetical participant, labeled P1–P3.

5. Other Varieties of Single-Case Experimental Designs

Other less commonly used designs within the family of SCEDs may be useful for personalized medicine. One of the most relevant may be the alternating treatment design ( Barlow & Hayes, 1979 ; Manolov et al., 2021 ), in which people are exposed to baseline and one or more treatments for very brief periods without the concern about stability before changing conditions. While the treatment period may be short, many more replications of treatments—and ineffective treatments—can be identified quickly. This type of design may be relevant for drugs that have rapid effects with a short half-life and behavioral interventions that have rapid effects ( Coyle & Robertson, 1998 )—for example, the effects of biofeedback on heart rate ( Weems, 1998 ). Another design is the changing criterion design, in which experimental control is demonstrated when the outcome meets certain preselected criteria that can be systematically increased or decreased over time ( Hartmann & Hall, 1976 ). The design is especially useful when learning a new skill or when outcomes change slowly over time ( Singh & Leung, 1988 )—for example, gradually increasing the range of foods chosen in a previously highly selective eater ( Russo et al., 2019 ).

6. Integrating Single-Case Experimental Designs Into Randomized Controlled Trials

SCEDs can be integrated into RCTs to compare the efficacy of treatments chosen for someone based on SCEDs versus a standardized or usual care treatment ( Epstein et al., 2021 ; Schork & Goetz, 2017 ). Such innovative designs may capture the best in SCEDs and randomized controlled designs. Kravitz et al. (2018) used an RCT in which one group ( n = 108) experienced a series of reversal AB conditions, or a personalized (N-of-1) trial. The specific conditions were chosen for each patient from among eight categories of treatments to reduce chronic musculoskeletal pain (e.g., acetaminophen, any nonsteroidal anti-inflammatory drug, acetaminophen/oxycodone, tramadol). The other group ( n = 107) received usual care. The study also incorporated mobile technology to record pain-related data daily (see Dallery et al., 2013 , for a discussion of technology and SCEDs). The results suggested that the N-of-1 approach was feasible and acceptable, but it did not yield statistically significant superior results in pain measures compared to the usual care group. However, as noted by Vohra and Punja (2019) , the results do not indicate a flaw in the methodological approach: finding that two treatments do not differ in superiority is a finding worth knowing.

Another example of a situation where an integrated approach may be useful is selecting a diet for weight control. Many diets for weight control that vary in their macronutrient intake—such as low carb, higher fat versus low fat, and higher carb—have their proponents and favorable biological mechanisms. However, direct comparisons of these diets basically show that they achieve similar weight control with large variability in outcome. Thus, while the average person on a low-fat diet does about the same as the average person on a lowcarb diet, some people on the low-carb diet do very well, while some fail. Some of the people who fail on the low-fat diet would undoubtedly do well on the low-carb diet, and some who fail on the low-fat diet would do well on the low-carb diet. Further, some would fail on both diets due to general problems in adherence.

Personalized medicine suggests that diets should be individualized to achieve the best results. SCEDs would be one way to show ‘proof of concept’ that a particular diet is better than a standard healthy diet. First, people would be randomized to experimental (including SCEDs) or control (not basing diet on SCEDs). Subject selection criteria would proceed as in any RCT. For the first 3 months, people in the experimental group would engage in individual reversal designs in which 2-week intervals of low-carb and low-fat diets would be interspersed with their usual eating, and weight loss, diet adherence, food preferences, and the reinforcing value of foods in the diet would be measured to assess biological, behavioral, and subjective changes.

Participants in the control group would experience a similar exposure to the different types of diets, but the diet to which they are assigned would be randomly chosen rather than chosen using SCED methods. In this way, they would have similar exposure to diets during the first 3 months of the study, but this experience would not impact group assignment. As with any RCT, the study would proceed with regular measures (e.g., 6, 12, 24 months) and the hypothesis that those assigned to a diet that results in better initial weight loss, and that they like and are motivated to continue, would do better than those receiving a randomly selected diet. The study could also be designed with three groups: a single-case design experimental group similar to the approach in the hypothetical study above and two control groups, one low-fat and one low-carb.

An alternative design would be to have everyone experience SCEDs for the first 3 months and then be randomized to either the optimal treatment identified during the first 3 months or an intervention randomly chosen among the interventions to be studied. This design has the advantage of randomization being after 3 months of study so that dropouts and non-adherers within the first 3 months would not be randomized in an intent-to-treat format.

The goal of either hypothesized study, or any study that attempts to incorporate SCEDs into RCTs, is that matching participants to treatments will provide superior results in comparison to providing the same treatment to everyone in a group. Two hypotheses can be generated in these types of designs: first, that the mean changes will differ between groups, and second, that the variability will differ between groups with less variability in outcome for people who have treatment selected after a single-case trial than people who have a treatment randomly selected. A reduction in variability plus mean differences in outcome should increase the effect size for people treated using individualized designs, increase power, and allow for a smaller sample size to ensure confidence about the differences observed between groups.

7. Limitations of Single-Case Experimental Designs

Single-case experimental designs have their common limitations. If a measure changes with repeated testing without intervention, it may not be useful for an SCED unless steps can be taken to mitigate such reactivity, such as more unobtrusive monitoring ( Kazdin, 2021 ). Given that the effects of interventions are evaluated over time, systematic environmental changes or maturation could influence the relationship between a treatment and outcome and thereby obscure the effect of a treatment. However, the design logic of reversal and multiple baseline designs largely control for such influences. Since SCEDs rely on repeated measures and a detailed study of the relationship between treatment and outcome, studies that use dependent measures that cannot be sampled frequently are not candidates for SCEDs. Likewise, the failure to identify a temporal relationship between the introduction of treatment and initiation of change in the outcome can make attribution of changes to the intervention challenging. A confounding variable’s association with introduction or removal of the intervention, which may cause inappropriate decisions about the effects of the intervention, is always possible. Dropout or uncontrolled events that occur to individuals can introduce confounding variables to the SCED. These problems are not unique to SCEDs and also occur with RCTs.

8. Single-Case Experimental Designs in Early Stage Translational Research

The emphasis of a research program may be on translating basic science findings to clinical interventions. The goal may be to collect early phase translational research as a step toward a fully powered RCT—( Epstein et al., 2021 ). The fact that a large amount of basic science does not get translated into clinical interventions is well known ( Butler, 2008 ; Seyhan, 2019 ); this served in part as the stimulus for the National Institutes of Health (NIH) to develop a network of clinical and translational science institutes in medical schools and universities throughout the United States. A common approach to early phase translational research is to implement a small, underpowered RCT to secure a ‘signal’ of a treatment effect and an effect size. This is a problematic approach to pilot research, and it is not advocated by the NIH as an approach to early phase translational research ( National Center for Complementary and Integrative Health, 2020 ). The number of participants needed for a fully powered RCT may be substantially different from the number projected from a small-sample RCT. These small, underpowered, early phase translational studies may provide too large an estimate of an effect size, leading to an underpowered RCT. Likewise, a small-sample RCT can lead to a small effect size that can, in turn, lead to a failure to implement a potentially effective intervention ( Kraemer et al., 2006 ). Therefore, SCEDs—especially reversal and multiple baseline designs—are evidently ideally suited to early phase translational research. This use complements the utility of SCEDs for identifying the optimal treatment for an individual or small group of individuals.

9. Conclusion

Single-case experimental designs provide flexible, rigorous, and cost-effective approaches that can be used in personalized medicine to identify the optimal treatment for an individual patient. SCEDs represent a broad array of designs, and personalized (N-of-1) designs are a prominent example, particularly in medicine. These designs can be incorporated into RCTs, and they can be integrated using meta-analysis techniques. SCEDs should become a standard part of the toolbox for clinical researchers to improve clinical care for their patients, and they can lead to the next generation of interventions that show maximal effects for individual cases as well as for early phase translational research to clinical practice.

Acknowledgments

We thank Lesleigh Stinson and Andrea Villegas for preparing the figures.

Disclosure Statement

Preparation of this special issue was supported by grants R01LM012836 from the National Library of Medicine of the National Institutes of Health and P30AG063786 from the National Institute on Aging of the National Institutes of Health. Funding to authors of this article was supported by grants U01 HL131552 from the National Heart, Lung, and Blood Institute, UH3 DK109543 from the National Institute of Diabetes, Digestive and Kidney Diseases, and RO1HD080292 and RO1HD088131 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The funders had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication. The views expressed in this paper are those of the authors and do not represent the views of the National Institutes of Health, the U.S. Department of Health and Human Services, or any other government entity.

• Abrahamyan L, Feldman BM, Tomlinson G, Faughnan ME, Johnson SR, Diamond IR, & Gupta S (2016). Alternative designs for clinical trials in rare diseases . American Journal of Medical Genetics, Part C: Seminars in Medical Genetics , 172 ( 4 ), 313–331. 10.1002/ajmg.c.31533 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Barlow DH, & Hayes SC (1979). Alternating treatments design: One strategy for comparing the effects of two treatments in a single subject . Journal of Applied Behavior Analysis , 12 ( 2 ), 199–210. 10.1901/jaba.1979.12-199 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Biglan A, Ary D, & Wagenaar AC (2000). The value of interrupted time-series experiments for community intervention research . Prevention Science , 1 ( 1 ), 31–49. 10.1023/a:1010024016308 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Boles RE, Roberts MC, & Vernberg EM (2008). Treating non-retentive encopresis with rewarded scheduled toilet visits . Behavior Analysis in Practice , 1 ( 2 ), 68–72. 10.1007/bf03391730 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Boring EG (1929). A history of experimental psychology . Appleton-Century-Crofts. [ Google Scholar ]
• Branch MN, & Pennypacker HS (2013). Generality and generalization of research findings. In Madden GJ, Dube WV, Hackenberg TD, Hanley GP, & Lattal KA (Eds.), APA handbook of behavior analysis, Vol. 1. Methods and principles (pp. 151–175). American Psychological Association. 10.1037/13937-007 [ CrossRef ] [ Google Scholar ]
• Butler D (2008). Translational research: Crossing the valley of death . Nature , 453 ( 7197 ), 840–842. 10.1038/453840a [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Byiers BJ, Reichle J, & Symons FJ (2012). Single-subject experimental design for evidence-based practice . American Journal of Speech-Language Pathology , 21 ( 4 ), 397–414. 10.1044/1058-0360(2012/11-0036) [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Coyle JA, & Robertson VJ (1998). Comparison of two passive mobilizing techniques following Colles’ fracture: A multi-element design . Manual Therapy , 3 ( 1 ), 34–41. 10.1054/math.1998.0314 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Cushing CC, Jensen CD, & Steele RG (2011). An evaluation of a personal electronic device to enhance self-monitoring adherence in a pediatric weight management program using a multiple baseline design . Journal of Pediatric Psychology , 36 ( 3 ), 301–307. 10.1093/jpepsy/jsq074 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Czajkowski SM, Powell LH, Adler N, Naar-king S, Reynolds KD, Hunter CM, Laraia B, Olster DH, Perna FM, Peterson JC, Epel E, Boyington JE, Charlson ME, Related O, Czajkowski SM, Powell LH, Adler N, Reynolds KD, Hunter CM, … Boyington JE (2015). From ideas to efficacy: The ORBIT model for developing behavioral treatments for chronic diseases . Health Psychology , 34 ( 10 ), 971–982. 10.1037/hea0000161 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Dallery J, Cassidy RN, & Raiff BR (2013). Single-case experimental designs to evaluate novel technology-based health interventions . Journal of Medical Internet Research , 15 ( 2 ), Article e22. 10.2196/jmir.2227 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Dallery J, & Raiff BR (2014). Optimizing behavioral health interventions with single-case designs: From development to dissemination . Translational Behavioral Medicine , 4 ( 3 ), 290–303. 10.1007/s13142-014-0258-z [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Davidson KW, Silverstein M, Cheung K, Paluch RA, & Epstein LH (2021). Experimental designs to optimize treatments for individuals . JAMA Pediatrics , 175 ( 4 ), 404–409. 10.1001/jamapediatrics.2020.5801 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Duan N, Kravitz RL, & Schmid CH (2013). Single-patient (n-of-1) trials: A pragmatic clinical decision methodology for patient-centered comparative effectiveness research . Journal of Clinical Epidemiology , 66 ( 8 Suppl ), S21–S28. 10.1016/j.jclinepi.2013.04.006 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Ebbinghaus H (1913). Memory; A contribution to experimental psychology . Teachers College, Columbia University. [ Google Scholar ]
• Epstein LH, Bickel WK, Czajkowski SM, Paluch RA, Moeyaert M, & Davidson KW (2021). Single case designs for early phase behavioral translational research in health psychology . Health Psychology , 40 ( 12 ), 858–874. 10.1037/hea0001055 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Fisher AJ, Medaglia JD, & Jeronimus BF (2018). Lack of group-to-individual generalizability is a threat to human subjects research . Proceedings of the National Academy of Sciences of the United States of America , 115 ( 27 ), E6106–E6115. 10.1073/pnas.1711978115 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Guyatt GH, Heyting A, Jaeschke R, Keller J, Adachi JD, & Roberts RS (1990). N of 1 randomized trials for investigating new drugs . Controlled Clinical Trials , 11 ( 2 ), 88–100. 10.1016/0197-2456(90)90003-k [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Hartmann D, & Hall RV (1976). The changing criterion design . Journal of Applied Behavior Analysis , 9 ( 4 ), 527–532. 10.1901/jaba.1976.9-527 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Hayes SC (1981). Single case experimental design and empirical clinical practice . Journal of Consulting and Clinical Psychology , 49 ( 2 ), 193–211. 10.1037/0022-006X.49.2.193 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Hekler E, Tiro JA, Hunter CM, & Nebeker C (2020). Precision health: The role of the social and behavioral sciences in advancing the vision . Annals of Behavioral Medicine , 54 ( 11 ), 805–826. 10.1093/abm/kaaa018 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Horner RD, & Baer DM (1978). Multiple-probe technique: A variation on the multiple baseline1 . Journal of Applied Behavior Analysis , 11 ( 1 ), 189–196. 10.1901/jaba.1978.11-189 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Horner RH, Carr EG, Halle J, McGee G, Odom S, & Wolery M (2005). The use of single-subject research to identify evidence-based practice in special education . Exceptional Children , 71 ( 2 ), 165–179. https://search.ebscohost.com/login.aspx?direct=true&db=psyh&AN=2004-22378-004&site=ehost-live [ Google Scholar ]
• Kazdin AE (2011). Single-case research designs: Methods for clinical and applied settings. In Single-case research designs: Methods for clinical and applied settings (2nd ed.). Oxford University Press. https://search.ebscohost.com/login.aspx?direct=true&db=psyh&AN=2010-18971-000&site=ehost-live [ Google Scholar ]
• Kazdin AE (2021). Single-case experimental designs: Characteristics, changes, and challenges . Journal of the Experimental Analysis of Behavior , 115 ( 1 ), 56–85. 10.1002/jeab.638 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Kraemer HC, Mintz J, Noda A, Tinklenberg J, & Yesavage JA (2006). Caution regarding the use of pilot studies to guide power calculations for study proposals . In Archives of General Psychiatry , 63 ( 5 ), 484–489. 10.1001/archpsyc.63.5.484 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Kratochwill TR, Hitchcock J, Horner RH, Levin JR, Odom SL, Rindskopf DM, & Shadish WR (2010). Single-case designs technical documentation . What Works Clearinghouse. [ Google Scholar ]
• Kratochwill TR & Levin JR (1992). Single-case research design and analysis: New directions for psychology and education . Lawrence Erlbaum. [ Google Scholar ]
• Kratochwill TR, & Levin JR (2010). Enhancing the scientific credibility of single-case intervention research: Randomization to the rescue . Psychological Methods , 15 ( 2 ), 124–144. 10.1037/a0017736 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Kratochwill TR, & Levin JR (2015). Single-case research design and analysis: New directions for psychology and education . Routledge. 10.4324/9781315725994 [ CrossRef ] [ Google Scholar ]
• Kratochwill TR, Hitchcock JH, Horner RH, Levin JR, Odom SL, Rindskopf DM, & Shadish WR (2013). Single-case intervention research design standards . Remedial and Special Education , 34 ( 1 ), 26–38. 10.1177/0741932512452794 [ CrossRef ] [ Google Scholar ]
• Kravitz R, & Duan N (2022). Conduct and implementation of personalized trials in research and practice . Harvard Data Science Review , ( Special Issue 3 ). 10.1162/99608f92.901255e7 [ CrossRef ] [ Google Scholar ]
• Kravitz RL, Schmid CH, Marois M, Wilsey B, Ward D, Hays RD, Duan N, Wang Y, MacDonald S, Jerant A, Servadio JL, Haddad D, & Sim I (2018). Effect of mobile device-supported single-patient multi-crossover trials on treatment of chronic musculoskeletal pain: A randomized clinical trial . JAMA Internal Medicine , 178 ( 10 ), 1368–1377. 10.1001/jamainternmed.2018.3981 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Lane-Brown A, & Tate R (2010). Evaluation of an intervention for apathy after traumatic brain injury: A multiple-baseline, single-case experimental design . Journal of Head Trauma Rehabilitation , 25 ( 6 ), 459–469. 10.1097/HTR.0b013e3181d98e1d [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Lillie EO, Patay B, Diamant J, Issell B, Topol EJ, & Schork NJ (2011). The n-of-1 clinical trial: the ultimate strategy for individualizing medicine? Personalized Medicine , 8 ( 2 ), 161–173. 10.2217/pme.11.7 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Lobo MA, Moeyaert M, Cunha AB, & Babik I (2017). Single-case design, analysis, and quality assessment for intervention research . Journal of Neurologic Physical Therapy , 41 ( 3 ), 187–197. 10.1097/NPT.0000000000000187 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Lundervold DA, & Belwood MF (2000). The best kept secret in counseling: Single-case (N = 1) experimental designs . Journal of Counseling and Development , 78 ( 1 ), 92–102. 10.1002/j.1556-6676.2000.tb02565.x [ CrossRef ] [ Google Scholar ]
• Manolov R, Tanious R, & Onghena P (2021). Quantitative techniques and graphical representations for interpreting results from alternating treatment design . Perspectives on Behavior Science . Advance online publication. 10.1007/s40614-021-00289-9 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• McDonald S, Quinn F, Vieira R, O’Brien N, White M, Johnston DW, & Sniehotta FF (2017). The state of the art and future opportunities for using longitudinal n-of-1 methods in health behaviour research: A systematic literature overview . Health Psychology Review , 11 ( 4 ), 307–323. 10.1080/17437199.2017.1316672 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Meredith SE, Grabinski MJ, & Dallery J (2011). Internet-based group contingency management to promote abstinence from cigarette smoking: A feasibility study . Drug and Alcohol Dependence , 118 ( 1 ), 23–30. 10.1016/j.drugalcdep.2011.02.012 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Miočević M, Klaassen F, Geuke G, Moeyaert M, & Maric M (2020). Using Bayesian methods to test mediators of intervention outcomes in single-case experimental designs . Evidence-Based Communication Assessment and Intervention , 14 ( 1–2 ), 52–68. 10.1080/17489539.2020.1732029 [ CrossRef ] [ Google Scholar ]
• Moeyaert M, & Fingerhut J (2022). Quantitative synthesis of personalized trials studies: Meta-analysis of aggregated data versus individual patient data . Harvard Data Science Review , ( Special Issue 3 ). 10.1162/99608f92.3574f1dc [ CrossRef ] [ Google Scholar ]
• Morgan DL, & Morgan RK (2001). Single-participant research design: Bringing science to managed care . American Psychologist , 56 ( 2 ), 119–127. 10.1037/0003-066X.56.2.119 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• National Center for Complementary and Integrative Health. (2020, May 18). Pilot studies: Common uses and misuses . National Institutes of Health. https://www.nccih.nih.gov/grants/pilot-studies-common-uses-andmisuses [ Google Scholar ]
• Normand MP (2016). Less is more: Psychologists can learn more by studying fewer people . In Frontiers in Psychology , 7 ( 94 ). 10.3389/fpsyg.2016.00934 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Pavlov IP (1927). Conditioned reflexes . Clarendon Press. [ Google Scholar ]
• Porcino A, & Vohra S (2022). N-of-1 trials, their reporting guidelines, and the advancement of open science principles . Harvard Data Science Review , ( Special Issue 3 ). 10.1162/99608f92.a65a257a [ CrossRef ] [ Google Scholar ]
• Pustejovsky JE (2019). Procedural sensitivities of effect sizes for single-case designs with directly observed behavioral outcome measures . Psychological Methods , 24 ( 2 ), 217–235. 10.1037/met0000179 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Riley AR, & Gaynor ST (2014). Identifying mechanisms of change: Utilizing single-participant methodology to better understand behavior therapy for child depression . Behavior Modification , 38 ( 5 ), 636–664. 10.1177/0145445514530756 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Riley WT, Glasgow RE, Etheredge L, & Abernethy AP (2013). Rapid, responsive, relevant (R3) research: A call for a rapid learning health research enterprise . Clinical and Translational Medicine , 2 ( 1 ), Article e10. 10.1186/2001-1326-2-10 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Roustit M, Giai J, Gaget O, Khouri C, Mouhib M, Lotito A, Blaise S, Seinturier C, Subtil F, Paris A, Cracowski C, Imbert B, Carpentier P, Vohra S, & Cracowski JL (2018). On-demand sildenafil as a treatment for raynaud phenomenon: A series of n -of-1 trials . Annals of Internal Medicine , 169 ( 10 ), 694–703. 10.7326/M18-0517 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Russo SR, Croner J, Smith S, Chirinos M, & Weiss MJ (2019). A further refinement of procedures addressing food selectivity . Behavioral Interventions , 34 ( 4 ), 495–503. 10.1002/bin.1686 [ CrossRef ] [ Google Scholar ]
• Schork NJ (2015). Personalized medicine: Time for one-person trials . Nature , 520 ( 7549 ), 609–611. 10.1038/520609a [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Schork N (2022). Accommodating serial correlation and sequential design elements in personalized studies and aggregated personalized studies . Harvard Data Science Review , ( Special Issue 3 ). 10.1162/99608f92.f1eef6f4 [ CrossRef ] [ Google Scholar ]
• Schork NJ, & Goetz LH (2017). Single-subject studies in translational nutrition research . Annual Review of Nutrition , 37 , 395–422. 10.1146/annurev-nutr-071816-064717 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Seyhan AA (2019). Lost in translation: The valley of death across preclinical and clinical divide – Identification of problems and overcoming obstacles . Translational Medicine Communications , 4 ( 1 ), Article 18. 10.1186/s41231-019-0050-7 [ CrossRef ] [ Google Scholar ]
• Shadish WR (2014). Analysis and meta-analysis of single-case designs: An introduction . Journal of School Psychology , 52 ( 2 ), 109–122. 10.1016/j.jsp.2013.11.009 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Shadish WR, Hedges LV, & Pustejovsky JE (2014). Analysis and meta-analysis of single-case designs with a standardized mean difference statistic: A primer and applications . Journal of School Psychology , 52 ( 2 ), 123–147. 10.1016/j.jsp.2013.11.005 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Sidman M (1960). Tactics of scientific research . Basic Books. [ Google Scholar ]
• Singh NN, & Leung JP (1988). Smoking cessation through cigarette-fading, self-recording, and contracting: Treatment, maintenance and long-term followup . Addictive Behaviors , 13 ( 1 ), 101–105. 10.1016/0306-4603(88)90033-0 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Soto PL (2020). Single-case experimental designs for behavioral neuroscience . Journal of the Experimental Analysis of Behavior , 114 ( 3 ), 447–467. 10.1002/jeab.633 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Van den Noortgate W, & Onghena P (2003). Hierarchical linear models for the quantitative integration of effect sizes in single-case research . Behavior Research Methods, Instruments, & Computers , 35 ( 1 ), 1–10. 10.3758/bf03195492 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Vannest KJ, Peltier C, & Haas A (2018). Results reporting in single case experiments and single case meta-analysis . Research in Developmental Disabilities , 79 , 10–18. 10.1016/j.ridd.2018.04.029 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Vlaeyen JWS, Wicksell RK, Simons LE, Gentili C, De TK, Tate RL, Vohra S, Punja S, Linton SJ, Sniehotta FF, & Onghena P (2020). From boulder to stockholm in 70 years: Single case experimental designs in clinical research . Psychological Record , 70 ( 4 ), 659–670. 10.1007/s40732-020-00402-5 [ CrossRef ] [ Google Scholar ]
• Vohra S, Punja S (2019). A case for n-of-1 trials . JAMA Internal Medicine , 179 ( 3 ), 452. 10.1001/jamainternmed.2018.7166 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Vohra S, Shamseer L, Sampson M, Bukutu C, Schmid CH, Tate R, Nikles J, Zucker DR, Kravitz R, Guyatt G, Altman DG, Moher D, & CENT Group (2016). CONSORT extension for reporting N-of-1 trials (CENT) 2015 Statement . Journal of Clinical Epidemiology , 76 , 9–17. 10.1016/j.jclinepi.2015.05.004 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Ward-Horner J, & Sturmey P (2010). Component analyses using single-subject experimental designs: A review . Journal of Applied Behavior Analysis , 43 ( 4 ), 685–704. 10.1901/jaba.2010.43-685 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Weems CF (1998). The evaluation of heart rate biofeedback using a multi-element design . Journal of Behavior Therapy and Experimental Psychiatry , 29 ( 2 ), 157–162. 10.1016/S0005-7916(98)00005-6 [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Wen X, Eiden RD, Justicia-Linde FE, Wang Y, Higgins ST, Thor N, Haghdel A, Peters AR, & Epstein LH (2019). A multicomponent behavioral intervention for smoking cessation during pregnancy: A nonconcurrent multiple-baseline design . Translational Behavioral Medicine , 9 ( 2 ), 308–318. 10.1093/tbm/iby027 [ PMC free article ] [ PubMed ] [ CrossRef ] [ Google Scholar ]
• Williams BA (2010). Perils of evidence-based medicine . Perspectives in Biology and Medicine , 53 ( 1 ), 106–120. 10.1353/pbm.0.0132 [ PubMed ] [ CrossRef ] [ Google Scholar ]

Baltimore bridge collapse: What happened and what is the death toll?

What is the death toll, when did the baltimore bridge collapse, why did the bridge collapse, who will pay for the damage and how much will the bridge cost.

HOW LONG WILL IT TAKE TO REBUILD THE BRIDGE?

What ship hit the baltimore bridge, what do we know about the bridge that collapsed.

HOW WILL THE BRIDGE COLLAPSE IMPACT THE BALTIMORE PORT?

Get weekly news and analysis on the U.S. elections and how it matters to the world with the newsletter On the Campaign Trail. Sign up here.

Writing by Lisa Shumaker; Editing by Daniel Wallis and Bill Berkrot

Our Standards: The Thomson Reuters Trust Principles. , opens new tab

Thomson Reuters

Lisa's journalism career spans two decades, and she currently serves as the Americas Day Editor for the Global News Desk. She played a pivotal role in tracking the COVID pandemic and leading initiatives in speed, headline writing and multimedia. She has worked closely with the finance and company news teams on major stories, such as the departures of Twitter CEO Jack Dorsey and Amazon’s Jeff Bezos and significant developments at Apple, Alphabet, Facebook and Tesla. Her dedication and hard work have been recognized with the 2010 Desk Editor of the Year award and a Journalist of the Year nomination in 2020. Lisa is passionate about visual and long-form storytelling. She holds a degree in both psychology and journalism from Penn State University.

Russia and Ukraine claimed to have downed each other's drones over the Black Sea on Monday, with both sides apparently devoting increasing attention to developing and using unmanned aircraft in their more than two-year-old war.

North Korea fired a ballistic missile off the east coast, South Korea's military said on Tuesday.

Postnatal outcome of fetal aberrant right subclavian artery: a single center study

• Maternal-Fetal Medicine
• Published: 30 March 2024

Cite this article

• Murat Kaya   ORCID: orcid.org/0000-0002-1251-1292 1  

Explore all metrics

This study aims to explore the correlation between fetal aberrant right subclavian artery (ARSA) and chromosomal disorders, with a specific focus on Down syndrome and DiGeorge syndrome.

From November 2017 to February 2020, we conducted fetal anomaly screening and assessed the fetal heart in 8494 at our institution. The right subclavian artery tracing was assessed using Doppler ultrasonography following the 3-vessel and tracheal views (3VTV) in the fetal heart scan.

ARSA was found in 31 fetuses, which accounts for 0.36% of the total of 8494 fetuses. 96.8% of fetuses with ARSA were found to have normal chromosomal analysis. We identified only one case of trisomy 21 as the chromosomal condition present. In 80% of the identified ARSA, there were no additional associated findings.

ARSA is a rare condition that often does not manifest any concomitant abnormalities. The majority of ARSA instances identified in the second trimester are euploid. If ARSA is the only sonographic finding during fetal anomaly screening and there are no maternal or laboratory risk factors, further evaluation with non-invasive diagnostics may be recommended. Non-invasive genetic testing may be used for additional investigation.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price includes VAT (Russian Federation)

Instant access to the full article PDF.

Rent this article via DeepDyve

Institutional subscriptions

Similar content being viewed by others

Significance of Fetal Aberrant Right Subclavian Artery and Comparison with Other Second Trimester Markers for Down Syndrome Screening

Seneesh Kumar Vikraman, Vipin Chandra, … Gopinathan Kannoly

Prenatal genetic analysis of fetal aberrant right subclavian artery with or without additional ultrasound anomalies in a third level referral center

Huili Xue, Lin Zhang, … Hailong Huang

Prenatal Diagnosis of Aberrant Right Subclavian Artery in Unselected North Indian Population: Significance and Counselling

Quaresima P, Fesslova V, Farina A, Kagan KO, Candiani M, Morelli M, Crispi F, Cavoretto PI (2023) How to do a fetal cardiac scan. Arch Gynecol Obstet 307(4):1269–1276. https://doi.org/10.1007/s00404-023-06951-8

Article   PubMed   Google Scholar  

Yoo SJ, Min JY, Lee YH, Roman K, Jaeggi E, Smallhorn J (2003) Fetal sonographic diagnosis of aortic arch anomalies. Ultrasound Obstetr Gynecol 22(5):535–546

Article   Google Scholar  

Chaoui R, Rake A, Heling K (2008) Aortic arch with four vessels: aberrant right subclavian artery. Ultrasound Obstetr Gynecol 31(1):115–117

Article   CAS   Google Scholar  

Scala S, Maggiore U, Candiani M, Venturini PL, Ferrero S, Greco T (2015) Aberrant right subclavian artery in fetuses with Down syndrome: a systematic review and meta‐analysis. Ultrasound Obstet Gynecol 46(3):266–276

Article   CAS   PubMed   Google Scholar  

Zapata H, Edwards JE, Titus JL (1993) Aberrant right subclavian artery with left aortic arch: associated cardiac anomalies. Pediatr Cardiol 14:159–161

Borenstein M, Minekawa R, Zidere V, Nicolaides KH, Allan LD (2010) Aberrant right subclavian artery at weeks of gestation a marker for chromosomal abnormality. Ultrasound Obstet Gynecol 36(5):548

Rembouskos G, Passamonti U, De Robertis V, Tempesta A, Campobasso G, Volpe G, Gentile M (2012) Aberrant right subclavian artery (ARSA) in unselected population at first and second trimester ultrasonography. Prenat Diagn 32(10):968–975

Gardiner H, Chaoui R (2013) The fetal three-vessel and tracheal view revisited. Semin Fetal Neonatal Med 18(5):261–268. https://doi.org/10.1016/j.siny.2013.01.007

Esmer AC, Gul A, Nehir A, Yuksel A, Dural O, Kalelioglu I, Has R, Demiroren T (2013) Detection rate of trisomy 21 in fetuses with isolated and non-isolated aberrant right subclavian artery. Fetal Diagn Ther 34(3):140–145. https://doi.org/10.1159/000354650

Polguj M, Chrzanowski L, Kasprzak JD, Stefańczyk L, Topol M (2014) The aberrant right subclavian artery (arteria lusoria): the morphological and clinical aspects of one of the most important variations—a systematic study of 141 reports. SciWorldJ 2014:292734

Google Scholar  

Chaoui R, Heling KS, Sarioglu N, Schwabe M, Dankof A, Bollmann R (2005) Aberrant right subclavian artery as a new cardiac sign in second-and third-trimester fetuses with Down syndrome. Am J Obstet Gynecol 192(1):257

Quarello E, Carvalho J (2009) Prenatal diagnosis of an aberrant right subclavian artery: four vessels arising from the aortic arch? Ultrasound Obstetr Gynecol 33(4):492–493

De León-Luis J, Bravo C, Gámez F, Ortiz-Quintana L (2012) Coronal view as a complementary ultrasound approach for prenatal diagnosis of aberrant right subclavian artery. Ultrasound Obstet Gynecol 40(3):370–371

Zalel Y, Achiron R, Yagel S, Kivilevitch Z (2008) Fetal aberrant right subclavian artery in normal and Down syndrome fetuses. Ultrasound Obstetri Gynecol 31(1):25

Fehmi Yazıcıoğlu H, Sevket O, Akın H, Aygün M, Özyurt ON, Karahasanoğlu A (2013) Aberrant right subclavian artery in Down syndrome fetuses. Prenat Diagn 33(3):209–213

Gul A, Corbacioglu A, Bakirci IT, Ceylan Y (2012) Associated anomalies and outcome of fetal aberrant right subclavian artery. Arch Gynecol Obstet 285:27–30

León J, Gámez F, Bravo C, Tenías JM, Arias Á, Pérez R, Maroto E (2014) Second‐trimester fetal aberrant right subclavian artery: original study, systematic review and meta‐analysis of performance in detection of Down syndrome. Ultrasound Obstet Gynecol 44(2):147

Cai M et al (2022) Fetal aberrant right subclavian artery: associated anomalies, genetic etiology, and postnatal outcomes in a retrospective cohort study. Front Pediatr 10:895562. https://doi.org/10.3389/fped.2022.895562

Article   PubMed   PubMed Central   Google Scholar  

Song MJ et al (2017) Prenatal diagnosis of aberrant right subclavian artery in an unselected population. Ultrasonography 36(3):278

Borenstein M et al (2008) Aberrant right subclavian artery at 11 + 0 to 13 + 6 weeks of gestation in chromosomally normal and abnormal fetuses. Ultrasound Obstet Gynecol 31(1):20–24

Martínez-Payo C, Suanzes E, Gómez-Manrique A, Arranz A, Pérez-Medina T (2022) Aberrant right subclavian artery as soft marker in the diagnosis of trisomy 21 during the first trimester of pregnancy. Arch Gynecol Obstet 305(6):1439–1444. https://doi.org/10.1007/s00404-021-06221-5

Şeker E, Yıldız GA (2023) A case of DiGeorge syndrome presenting with a cervical aortic arch. Arch Gynecol Obstet 307(4):1185–1186

Luo T et al (2023) Associated congenital anomalies and genetic anomalies in fetuses with isolated and non-isolated aberrant right subclavian artery. J Matern Fetal Neonatal Med 36(1):2211705

Download references

Acknowledgements

I express my gratitude to Doctor Atıf Kılıç, a radiologist, with whom I collaborated. Additionally, I would like to express my gratitude to Associate Professor Seçil Karaca Kurtulmuş, a perinatologist, for her valuable contributions.

Author information

Authors and affiliations.

Gaziantep City Hospital Radiology Department, University of Health Science, Ibn-I Sina District, 27470, Şahinbey/Gaziantep, Turkey

You can also search for this author in PubMed   Google Scholar

Corresponding author

Correspondence to Murat Kaya .

Ethics declarations

Conflict of interest, ethical statement.

We obtained approval from our institution.

Additional information

Publisher's note.

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Kaya, M. Postnatal outcome of fetal aberrant right subclavian artery: a single center study. Arch Gynecol Obstet (2024). https://doi.org/10.1007/s00404-024-07488-0

Download citation

Received : 02 February 2024

Accepted : 16 March 2024

Published : 30 March 2024

DOI : https://doi.org/10.1007/s00404-024-07488-0

Share this article

Anyone you share the following link with will be able to read this content:

Sorry, a shareable link is not currently available for this article.

Provided by the Springer Nature SharedIt content-sharing initiative

• Find a journal
• Publish with us
• Track your research