Case Study Designs

Objectives After completing this module, you will be able to:

  • Understand the kinds of research questions that can be answered through explanatory case study designs;
  • Identify inappropriate or inadequate uses of the case study designs, including studies labeled "case study" that fail to meet the requirements for the design;
  • Take steps to reduce the threats to internal and external validity inherent in case study designs, particularly the threats that result from limited ability to anticipate unanticipated or accounted for differences among groups that threaten the validity of results;
  • Assess the explanatory power, and internal and external validity of case study designs;
  • Evaluate the quality of sampling strategies used in these designs and develop sampling strategies to help ensure that samples are adequate and that the samples for comparison groups are reasonable;
  • Create exploratory and explanatory case study designs to answer research and evaluation questions.

Note: This is a much-maligned group. Some researchers call anything a case study and there is a general tendency to fail to distinguish between the purely descriptive "case study as a story" and exploratory and explanatory case studies. Exploratory case studies often do not use comparison groups. They tend to focus on identifying key features of a given phenomenon or outcome that will form the basis for further research. Explanatory case studies require multiple cases and they also often require that those cases constitute comparison groups.

Assigned Materials

Topic 1: What is a case study DESIGN (not method, not sampling approach, but design)?

Learning Guide: Case Study Designs -- My questions are based on Yin's concepts

Yin, R.K. (2009) Case Study Research. 4th Edition. Chapter 2, Designing Case Studies: Identifying Your Cases and Establishing the Logic of Your Case Study, pp. 24-65. E-reserve

Baxter, P. & Jack, S. (2008) Qualitative case study methodology: Study design and implementation for novice researchers. The Qualitative Report 13(4), 544-559. Baxter & Jack build on Yin and largely the three authors agree on most of the critical aspects of case study research designs. However, the Baxter & Jack article also exposes some of the problems in discussing case study designs. One example is Table 2 on p. 547. This table includes a long list of types of case studies, whereas Yin uses an approach based on embedded versus holistic units and number of comparison groups. I find the Baxter & Jack approach both helpful and confusing. In some ways it does more to distinguish between explanatory, exploratory and descriptive case study designs than does Yin, but it also introduces some confusion -- at least to me. For example, they say that one type of case study is "descriptive" meaning that the case study "...is used to describe an intervention or phenomenon and the real-life context in which it occurred," a definition they attribute to Yin. However, later in the same table they refer to the "intrinsic type" of case study. Their description is lengthy, but basically -- it seems to me -- they are saying a descriptive case study that consists of a single case. Table 3 is excellent and will help you develop propositions (kind of like hypotheses, but the qualitative version) for a case study if you decide to use qualitative data analysis in your work in the future. The article is easier to read than Yin -- you might want to read it first.

Slide show about Case Study Designs

Topic 2: Where do case studies "fit" in my research program? Will I ever really use one?

Have a copy of Comparative Characteristics of Design Groups in class. I will pose some qeustions to you based on this document.

Additional Materials -- including good information on sampling and data analysis for case studies. I still do not see many of you taking advantage of thsoe extra credit points. I strongly encourage you to explore at least one of these articles.

Almutairi, A.F., Gardner, G.E. & McCarthy, A. (2014) Practical guidance for the use of pattern-matching technique in case-study research: A case presentation. Nursing & Health Sciences 16(2), 239-244. DOI: 10.1111/nhs.12096.

Barratt, M.J. & Lenton, S. (2015) Representativeness of online purposive sampling with Australian cannabis cultivators. International Journal of Drug Policy 26(3), 323-326. DOI: 10.1016/j.drugpo.2014.10.007. DOI: 10.1177/1525822X14526838.

Barratt, M.J., Ferris, J.A. & Lenton, S. (2015) Hidden populations, online purposive sampling, and external validity: Taking off the blindfold. Field Methods 27(1), 3-21. DOI: 10.1177/1525822X14526838

Benoot, C., Hannes, K. & Bilsen, J. (2016) The use of purposeful sampling in qualitative evidence synthesis: A worked example on sexual adjustment to a cancer trajectory. BMC Medical Research Methodology 16, 1-12. DOI: 10.1186/s12874-016-0114-6.

Elman, C., Gerring, J. & Mahoney, J. (2016) Case study research: Putting the quant into the qual. Sociological Methods & Research. 45(3), 375-391. DOI: 10.1177/0049124116644273.

Kamholz, B.W., Gulliver, S.B., Helstrom, A. et al. (2009) Implications of participant self-selection for generalizability: Who participates in smoking laboratory research. Substance Use and Misuse 44(3), 343-356. DOI: 10.1080/10826080802345051.

Killingback, C., Tsofliou, F. & Clark, C. (2017) Older people's adherence to community-based group exercise programmes: A multiple-case study. BMC Public Health 17 (January 25):12. DOI 10.1186/s12889-017-4049-6

McInroy, L.B. (2016) Pitfalls, potentials and ethics of online survey research: LGBTQ and other marginalized and hard-to-access youths. Social Work Research 40(2), 83-93. DOI: 10.1093/swr/svw005

Perakla, A. (2004) Reliability and validity in research based on naturally occurring social interaction. In D. Silverman (Ed.), Qualitative Research: Theory, Method and Practice (pp. 283-304). London: Sage Publications. E-reserve

Rule, P., John, V.M. (2015) A necessary dialogue: Theory in case study research. International Journal of Qualitative Methods 14(4), 1-11. DOI: 10.1177/1609406915611575.

Topp, L., Barker, B. & Degenhardt, L. (2004) The external validity of results derived from ecstasy users recruited usingn purposive sampling strategies. Drug & Alcohol Dependence 73(1), 33-41. DOI: 10.1016/j.drugalcdep.2003.09.001.

Unicomb, R., Colyvas, K., Harrison, E. & Hewat, S. (2015) Assessment of reliable change using 95% credible intervals for the differences in proportions: A statistical analysis for case-study methodology. Journal of Speech, Language & Hearing Research 58(3), 728-739. DOI: 10.1044/2015_JSLHR-S-14-0158.

van Hoeven, L.R., Janssen, M.P., Roes, K.C.B. & Koffijberg, H. (2015) Aiming for a representative sample: Simulating random versus purposive strategies for hospital selection. BMC Medical Research Methodology 15, 1-9. DOI: 10.1186/s12874-015-0089-8.

Walia, R., Bhansali, A. Ravikiran, M. et al. (2014) Self weighing and non-probability samples. Indian Journal of Medical Research 140(1), 150-151.