Case study
A case study is an in-depth, detailed examination of a particular case (or cases) within a real-world context.
Generally, a case study can highlight nearly any individual, group, organization, event, belief system, or action. A case study does not necessarily have to be one observation (
Case study research has been extensively practiced in both the social and natural sciences.[8][9]: 5–6 [10][11]
Definition
There are multiple definitions of case studies, which may emphasize the number of observations (a small N), the method (qualitative), the thickness of the research (a comprehensive examination of a phenomenon and its context), and the naturalism (a "real-life context" is being examined) involved in the research.[12] There is general agreement among scholars that a case study does not necessarily have to entail one observation (N=1), but can include many observations within a single case or across numerous cases.[3][4][5][6] For example, a case study of the French Revolution would at the bare minimum be an observation of two observations: France before and after a revolution.[13] John Gerring writes that the N=1 research design is so rare in practice that it amounts to a "myth".[13]
The term cross-case research is frequently used for studies of multiple cases, whereas within-case research is frequently used for a single case study.[5][7]
John Gerring defines the case study approach as an "intensive study of a single unit or a small number of units (the cases), for the purpose of understanding a larger class of similar units (a population of cases)".[14] According to Gerring, case studies lend themselves to an idiographic style of analysis, whereas quantitative work lends itself to a nomothetic style of analysis.[15] He adds that "the defining feature of qualitative work is its use of noncomparable observations—observations that pertain to different aspects of a causal or descriptive question", whereas quantitative observations are comparable.[15]
According to John Gerring, the key characteristic that distinguishes case studies from all other methods is the "reliance on evidence drawn from a single case and its attempts, at the same time, to illuminate features of a broader set of cases".[13] Scholars use case studies to shed light on a "class" of phenomena.
Research designs
As with other social science methods, no single research design dominates case study research. Case studies can use at least four types of designs. First, there may be a "no theory first" type of case
While case studies can be intended to provide bounded explanations of single cases or phenomena, they are often intended to raise theoretical insights about the features of a broader population.[20]
Case selection and structure
Case selection in case study research is generally intended to find cases that are representative samples and which have variations on the dimensions of theoretical interest.[20] Using that is solely representative, such as an average or typical case is often not the richest in information. In clarifying lines of history and causation it is more useful to select subjects that offer an interesting, unusual, or particularly revealing set of circumstances. A case selection that is based on representativeness will seldom be able to produce these kinds of insights.
While a random selection of cases is a valid case selection strategy in large-N research, there is a consensus among scholars that it risks generating serious biases in small-N research.[21][22][20][23] Random selection of cases may produce unrepresentative cases, as well as uninformative cases.[23] Cases should generally be chosen that have a high expected information gain.[24][20][25] For example, outlier cases (those which are extreme, deviant or atypical) can reveal more information than the potentially representative case.[25][26][27] A case may also be chosen because of the inherent interest of the case or the circumstances surrounding it. Alternatively, it may be chosen because of researchers' in-depth local knowledge; where researchers have this local knowledge they are in a position to "soak and poke" as Richard Fenno put it,[28] and thereby to offer reasoned lines of explanation based on this rich knowledge of setting and circumstances.
Beyond decisions about case selection and the subject and object of the study, decisions need to be made about the purpose, approach, and process of the case study. Gary Thomas thus proposes a typology for the case study wherein purposes are first identified (evaluative or exploratory), then approaches are delineated (theory-testing, theory-building, or illustrative), then processes are decided upon, with a principal choice being between whether the study is to be single or multiple, and choices also about whether the study is to be retrospective, snapshot or diachronic, and whether it is nested, parallel or sequential.[29]
In a 2015 article, John Gerring and Jason Seawright list seven case selection strategies:[20]
- Typical cases are cases that exemplify a stable cross-case relationship. These cases are representative of the larger population of cases, and the purpose of the study is to look within the case rather than compare it with other cases.
- Diverse cases are cases that have variations on the relevant X and Y variables. Due to the range of variation on the relevant variables, these cases are representative of the full population of cases.
- Extreme cases are cases that have an extreme value on the X or Y variable relative to other cases.
- Deviant cases are cases that defy existing theories and common sense. They not only have extreme values on X or Y (like extreme cases) but defy existing knowledge about causal relations.
- Influential cases are cases that are central to a model or theory (for example, Nazi Germany in theories of fascism and the far-right).
- Most similar cases are cases that are similar on all the independent variables, except the one of interest to the researcher.
- Most different cases are cases that are different on all the independent variables, except the one of interest to the researcher.
For theoretical discovery, Jason Seawright recommends using deviant cases or extreme cases that have an extreme value on the X variable.[25]
Arend Lijphart, and Harry Eckstein identified five types of case study research designs (depending on the research objectives), Alexander George and Andrew Bennett added a sixth category:[30]
- Atheoretical (or configurative idiographic) case studies aim to describe a case very well, but not to contribute to a theory.
- Interpretative (or disciplined configurative) case studies aim to use established theories to explain a specific case.
- Hypothesis-generating (or heuristic) case studies aim to inductively identify new variables, hypotheses, causal mechanisms, and causal paths.
- Theory testing case studies aim to assess the validity and scope conditions of existing theories.
- Plausibility probes, aim to assess the plausibility of new hypotheses and theories.
- Building block studies of types or subtypes, aim to identify common patterns across cases.
Aaron Rapport reformulated "least-likely" and "most-likely" case selection strategies into the "countervailing conditions" case selection strategy. The countervailing conditions case selection strategy has three components:[31]
- The chosen cases fall within the scope conditions of both the primary theory being tested and the competing alternative hypotheses.
- For the theories being tested, the analyst must derive clearly stated expected outcomes.
- In determining how difficult a test is, the analyst should identify the strength of countervailing conditions in the chosen cases.
In terms of case selection,
King, Keohane, and Verba argue that there is no methodological problem in selecting the
Uses
Case studies have commonly been seen as a fruitful way to come up with hypotheses and generate theories.
Case studies are also useful for formulating concepts, which are an important aspect of theory construction.[37] The concepts used in qualitative research will tend to have higher conceptual validity than concepts used in quantitative research (due to conceptual stretching: the unintentional comparison of dissimilar cases).[24] Case studies add descriptive richness,[38][33] and can have greater internal validity than quantitative studies.[39] Case studies are suited to explain outcomes in individual cases, which is something that quantitative methods are less equipped to do.[32]
Case studies have been characterized as useful to assess the plausibility of arguments that explain empirical regularities.[40] Case studies are also useful for understanding outliers or deviant cases.[36]
Through fine-gained knowledge and description, case studies can fully specify the causal mechanisms in a way that may be harder in a large-N study.[41][38][42][21][43][36] In terms of identifying "causal mechanisms", some scholars distinguish between "weak" and "strong chains". Strong chains actively connect elements of the causal chain to produce an outcome whereas weak chains are just intervening variables.[44]
Case studies of cases that defy existing theoretical expectations may contribute knowledge by delineating why the cases violate theoretical predictions and specifying the scope conditions of the theory.
Qualitative research may be necessary to determine whether a treatment is as-if random or not. As a consequence, good quantitative observational research often entails a qualitative component.[15]
Limitations
Designing Social Inquiry (also called "KKV"), an influential 1994 book written by Gary King, Robert Keohane, and Sidney Verba, primarily applies lessons from regression-oriented analysis to qualitative research, arguing that the same logics of causal inference can be used in both types of research.[22][48][37] The authors' recommendation is to increase the number of observations (a recommendation that Barbara Geddes also makes in Paradigms and Sand Castles),[34] because few observations make it harder to estimate multiple causal effects, as well as increase the risk that there is measurement error, and that an event in a single case was caused by random error or unobservable factors.[22] KKV sees process-tracing and qualitative research as being "unable to yield strong causal inference" due to the fact that qualitative scholars would struggle with determining which of many intervening variables truly links the independent variable with a dependent variable. The primary problem is that qualitative research lacks a sufficient number of observations to properly estimate the effects of an independent variable. They write that the number of observations could be increased through various means, but that would simultaneously lead to another problem: that the number of variables would increase and thus reduce degrees of freedom.[37] Christopher H. Achen and Duncan Snidal similarly argue that case studies are not useful for theory construction and theory testing.[49]
The purported "degrees of freedom" problem that KKV identify is widely considered flawed; while quantitative scholars try to aggregate variables to reduce the number of variables and thus increase the degrees of freedom, qualitative scholars intentionally want their variables to have many different attributes and complexity.[50][24] For example, James Mahoney writes, "the Bayesian nature of process of tracing explains why it is inappropriate to view qualitative research as suffering from a small-N problem and certain standard causal identification problems."[51] By using Bayesian probability, it may be possible to makes strong causal inferences from a small sliver of data.[52][53]
KKV also identify inductive reasoning in qualitative research as a problem, arguing that scholars should not revise hypotheses during or after data has been collected because it allows for ad hoc theoretical adjustments to fit the collected data.[54] However, scholars have pushed back on this claim, noting that inductive reasoning is a legitimate practice (both in qualitative and quantitative research).[55]
A commonly described limit of case studies is that they do not lend themselves to generalizability.[22] Due to the small number of cases, it may be harder to ensure that the chosen cases are representative of the larger population.[39]
As small-N research should not rely on random sampling, scholars must be careful in avoiding selection bias when picking suitable cases.[21] A common criticism of qualitative scholarship is that cases are chosen because they are consistent with the scholar's preconceived notions, resulting in biased research.[21] Alexander George and Andrew Bennett also note that a common problem in case study research is that of reconciling conflicting interpretations of the same data.[24] Another limit of case study research is that it can be hard to estimate the magnitude of causal effects.[56]
Teaching case studies
Teachers may prepare a case study that will then be used in classrooms in the form of a "teaching" case study (also see
Outside of law, teaching case studies have become popular in many different fields and professions, ranging from business education to science education. The Harvard Business School has been among the most prominent developers and users of teaching case studies.[59][60] Teachers develop case studies with particular learning objectives in mind. Additional relevant documentation, such as financial statements, time-lines, short biographies, and multimedia supplements (such as video-recordings of interviews) often accompany the case studies. Similarly, teaching case studies have become increasingly popular in science education, covering different biological and physical sciences. The National Center for Case Studies in Teaching Science has made a growing body of teaching case studies available for classroom use, for university as well as secondary school coursework.[61][62]
See also
References
- OCLC 12235475.
- OCLC 22909879.
- ^ ISBN 978-0-472-09835-4.
- ^ ISBN 978-1-4008-2121-1.
- ^ ISBN 978-0-521-85928-8.
- ^ JSTOR 44218229.
- ^ ISBN 978-0-262-57222-4.
- ISBN 978-1-4129-5670-3.
- ^ ISBN 978-1-5063-3616-9.
- ^ Rolls, Geoffrey (2005). Classic Case Studies in Psychology. Abingdon, England: Hodder Education.
- ISBN 978-1786437235.
- ISBN 978-0-521-85928-8.
- ^ ISBN 978-0-521-85928-8.
- ISBN 978-0-521-85928-8.
- ^ ISSN 1094-2939.
- ^ ISSN 2198-2627.
- JSTOR 258921.
- ISBN 978-0-8039-5767-1.
- ISBN 978-0-520-94338-4.
- ^ ISBN 978-1-4462-7448-4
- ^ ISBN 978-1-4462-7448-4
- ^ a b c d e f g King, Gary/ Keohane, Robert O./ Verba, Sidney: Designing Social Inquiry. Scientific Inference in Qualitative Research. Princeton University Press, 1994.
- ^ ISBN 978-0-521-85928-8.
Random sampling is unreliable in small-N research
- ^ OCLC 944521872.
- ^ ISBN 978-1-107-09771-1, retrieved 2021-02-11
- ^ Huang, Huayi (2015). Development of New Methods to Support Systemic Incident Analysis (PDF) (Doctoral dissertation). London: Queen Mary University.[page needed]
- .
- S2CID 145630377.
- S2CID 144895919.
- OCLC 944521872.
- S2CID 131769695.
- ^ ISBN 978-0-691-14970-7.
- ^ OCLC 838295613.
- ^ JSTOR 10.3998/mpub.11910.
- ^ ISBN 978-0-521-85928-8.
- ^ ISBN 978-1-108-42727-2
- ^ S2CID 43923978.
- ^ ISSN 1049-0965.
- ^ ISBN 978-0-521-85928-8.
- ISBN 978-0-19-960445-6. Archivedfrom the original on 2014-05-30.
- ISSN 1094-2939.
- ^ Braumoeller, Bear and Anne Sartori. 2004. "The Promise and Perils of Statistics in International Relations." in Cases, Numbers, Models: International Relations Research Methods. Ann Arbor: University of Michigan Press: ch. 6.
- ISBN 978-0-521-85928-8.
- S2CID 143163960.
- ISBN 978-0-521-85928-8.
- S2CID 145230528.
- ISBN 978-0-521-85928-8.
- S2CID 1846974.
- S2CID 153591618.
- ISBN 9780199286546. Retrieved 2021-02-19.
- S2CID 156167903.
- ISBN 9780199286546. Archivedfrom the original on 2014-08-04.
- ISBN 978-1-108-42164-5.
- ISBN 978-1-4008-2121-1.
- S2CID 143936902.
- ISBN 978-0-521-85928-8.
- OCLC 261174163.
- ^ Jackson, Giles (2011). "Rethinking the case method". Journal of Management Policy and Practice. 12 (5): 142–64.
- ^ Garvin, David A. (2003). "Making the Case: Professional Education for the World of Practice". Harvard Magazine. 106 (1): 56–107.
- ISBN 978-1-422-10158-2.[page needed]
- ISBN 9781909818569. Retrieved 2024-09-27.
- ^ Herreid, Clyde F.; Schiller, Nancy A.; Wright, Carolyn; Herreid, Ky (eds.). "About Us". National Center for Case Study Teaching in Science (NCCSTS). University at Buffalo. Archived from the original on 2018-09-13. Retrieved 2018-09-12.
Further reading
- Baskarada, Sasa (October 19, 2014). "Qualitative Case Study Guidelines". The Qualitative Report. 19 (40): 1–25. SSRN 2559424.
- Bartlett, L. and Vavrus, F. (2017). Rethinking Case Study Research. Routledge.
- Baxter, Pamela; Jack, Susan (2008). "Qualitative Case Study Methodology: Study Design and Implementation for Novice Researchers". The Qualitative Report. 13 (4): 544–59.
- JSTOR 258557.
- George, Alexander L. and Bennett, Andrew. (2005) Case studies and theory development in the social sciences. MIT Press. ISBN 0-262-57222-2
- Gerring, John. (2008) Case Study Research. New York: Cambridge University Press. ISBN 978-0-521-67656-4
- Kyburz-Graber, Regula (2004). "Does case-study methodology lack rigour? The need for quality criteria for sound case-study research, as illustrated by a recent case in secondary and higher education". Environmental Education Research. 10 (1): 53–65. S2CID 218499108.
- Mills, Albert J.; Durepos, Gabrielle; Wiebe, Elden, eds. (2010). Encyclopedia of Case Study Research. SAGE Publications. ISBN 978-1-4129-5670-3.
- Ragin, Charles C. and Becker, Howard S. Eds. (1992) What is a Case? Exploring the Foundations of Social Inquiry. Cambridge University Press. ISBN 0-521-42188-8
- Scholz, Roland W. and Tietje, Olaf. (2002) Embedded Case Study Methods. Integrating Quantitative and Qualitative Knowledge. Sage. ISBN 0-7619-1946-5
- Straits, Bruce C. and Singleton, Royce A. (2004) Approaches to Social Research, 4th ed. Oxford University Press. ISBN 0-19-514794-4.
- Thomas, Gary (2011). How to Do Your Case Study: A Guide for Students and Researchers. SAGE Publications.
- Yin, Robert K (October 2017). Case study research: design and methods (6th ed.). Thousand Oaks, California, US: SAGE Publications. ISBN 978-1-5063-3616-9.