Characteristics of a Case Study

Although case study research may be applied to many settings for many reasons, in this chapter we will focus on its use in illuminating educational and social programs. Program case study designs begin by identifying the specific program to be investigated followed by the selection of specific aspects that will be thoroughly studied. Unless very small and uncomplicated, most programs cannot be studied in their entirety. The selected program elements are then clarified using research questions that will guide the actual case study. Answering these questions through several forms of data collection becomes the principal task of the case study researcher.

Bounding the Case

Case study research involves the exploration of something with clear limits or boundaries. The case study researcher carefully defines and clearly specifies what elements of the case will be studied, that is, which portion of the program or other phenomena is to be the focus of the investigation. This bounding of the case includes identifying the aspects to be studied using research questions, the time frame to be included, and the exact physical locations that are part of the research. Such bounding communicates those parts of the case that will be included and those that will be excluded from the study. Identifying the study's location, the program within the facility to be observed, and the time frame within which the study will be conducted, for example, may bound a case study of a county mental health facility. In this study, the researcher could select the emergency care program within the mental health facility and decide to conduct the case study for at least three months to obtain a good sample of the facility's operation.

Focusing, limiting, or bounding case study efforts allows the researcher to use valuable investigative time for in-depth observations that produce rich and detailed case descriptions. These study limits are necessary given the usual time and resource constraints of any research effort.

Purposes of Case Studies

Lapan and Armfield (2009) note that many different purposes for case study research have been identified in the literature, including its ability to explain, explore, describe, and compare educational or social programs (Yin, 2003) and “to discover and communicate innovative ideas and programs” (Simons, 1977, in Lapan & Armfield, 2009, p. 167). Stake (1995,2006) has provided one of the most efficient ways of explaining the purposes of case study research, recognizing it to be either intrinsic or instrumental.

Intrinsic case studies, on the one hand, focus on the case being studied, answering questions about that entity only to communicate the illuminated operations to its participants and other stakeholders. Instrumental case studies, on the other hand, use case results to support a theory or construct a new way of explaining some phenomenon.

In researching one or more reading classes for first graders, for example, an intrinsic case study researcher would observe several selected program elements during at least part of the school year and then summarize these findings to offer participants (teachers, parents, administrators) a deeper understanding about the program's operation. This intrinsic purpose would be served by focusing exclusively on the program itself.

Instrumental case studies, by contrast, explore instances or cases to build new theories or compare findings to current ones to either corroborate them or question their validity. In the first-grade reading example, the instrumental case study researcher would ordinarily collect data from dozens of classrooms, developing rich descriptions of teaching and learning patterns. By using large amounts of concrete data from real-life contexts, the theory-building or theory-testing case study researcher may be able to generate new or supporting explanations (theories) of how first graders learn to read.

Case Study Types

Case studies can be designed to include either one or several cases of the same phenomenon and can be conducted at any number of sites. Single case studies are those conducted using just one incidence or example of the case at a single site (one health care facility, one reading classroom). Multiple case studies can be conducted at one site where many examples of the case are examined, such as several first-grade reading classes in one school, or at multiple sites, such as first-grade reading classes in different schools or school districts. Multiple case studies and multiple site case studies are usually designed for purposes of comparison and sometimes referred to as comparative case studies. Whether at one or multiple sites, multiple cases are considered to be examples of the same type of case sharing common characteristics. Thus one might conduct a multiple comparative case study of state-level immigration policies in Arizona, Texas, New Mexico, and California, or of multiple high school drug prevention programs at five or six different high schools.

Most case studies, regardless of the design, can be completed in six weeks to three months depending on the number of researchers and the complexity of the case. However, some case study research can be designed for longer periods, perhaps for six months to more than a year, and are often called longitudinal case studies.