Case Study


Unlike the other approaches we discuss, case study research does not emerge from a particular social scientific tradition.  Additionally, case studies can be qualitative and/or quantitative.  It is quite likely, as Stake (1994) points out, that researchers doing case study research are calling it by another name.  Case studies, as a research design, are also being conducted across disciplines and research traditions.

Case studies have been considered a research strategy or design, an evaluation method, and a reporting mode.  We felt case study research was important to define because it is a common approach in healthcare research.  In part, this may be because the units of interest in healthcare research (patient, practice, health system) can often be easily bounded and seen by the researcher as a case.


"Case study is defined by individual cases, not by the methods of inquiry used." (Stake, 1994, p. 236)

A case can be "whatever bounded system (to use Louis Smith's term) is of interest." (Stake, 1983, p. 283.)

The investigators identify the boundaries, and these boundaries (what is and what is not a case) are continually kept in focus.

A case may be simple or complex.  It may be a single patient, a practice, a health care system. 

The goal in case study research is to understand the boundaries of the case and the complexity of the behavior patterns of the bounded system. 

Researchers may study a single case or mutiple cases.  In multiple case studies, researchers study cases in depth individually as well as look across cases for similarities and differences.

Common Methods used in Case Study Research

The goal of case study research is to understand the complexity of a case in the most complete way possible.  For this reason, case study research often involves the use of multiple methods for collecting data.  By using multiple sources of data (and both qualitative and quantitative data) researchers may attain the richest possible understanding of a case. The qualitative methods described below are all likely to be used in case study research.

Participant Observation. This involves the researcher immersing him or herself in the daily lives and routines of those being studied.  This often requires extensive work in the setting being studied.  This is called fieldwork. Observation provides insight into the behavior patterns and social organizations that operate and constitute a particular bounded system or case.

Interviewing. Researchers will learn about the person or persons that are part of the case by speaking with these people.  Talking with informants is called interviewing.  The types of interviews conducted by researchers vary in degree of formality (informal interview to semi-structured to structured interviews).

Collection of Artifacts and Texts. Researchers may also learn about a bounded system by collecting and studying artifacts (e.g. written protocols, charts, flowsheets, educational handouts) - materials used by members of the system or case being studied. 

Stake (1994) identifies three types of case studies:

  • Intrinsic - aimed at understanding a particular case because the case itself is of interest (e.g. how one person managed a stroke).  A case may be of interest because it has particular features or because it is ordinary.
  • Instrumental - aimed at providing insight into an issue or problem or to refine a theory.  In this instance, understanding the complexities of the case is secondary to understanding something else (e.g. case study of 'Sally' provides insights into the problems with healthcare in the US).
  • Collective - a number of cases are studies jointly in order to understand a phenomenon, population or general condition.  Often referred to as a multiple-case study (e.g. 15 primary care practices are studied as single but conjoined cases in order to understand how obesity is discussed in this setting).


Crabtree, BF & Miller, WL. (1999). "Researching practice settings: A case study approach." In BF Crabtree and WL Miller (Eds.) Doing Qualitative Research (2nd edition, pp. 293-312). Thousand Oaks, CA. Sage Publications.

Mariano, C. (2001). "Case Study The Method." In Nursing Research: A Qualitative Perspective. PL Munhall (Ed.) pp. 359-384. Boston, MA: Jones and Bartlett Publishers.

Merriam, S. (1998). Case Study Research in Education: A Qualitative Approach. San Francisco: Jossey-Bass.

Patton, MQ. (1990). Qualitative Evaluation and Research Methods (2nd ed.) Newbury Park, CA: Sage Publications.

Stake, RE. (1994). Case Studies. In NK Denzin & YS Lincoln (Eds.) Handbook of Qualitative Research (pp. 236-247). Thousand Oaks, Sage Publications.

Stake, RE. (1995). The Art of Case Study Research. Thousand Oaks, CA: Sage Publications.

Yin, RK. (1989). Case Study Research: Design and Methods (2nd ed.). Newbury Park, CA: Sage Publications.

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