A Review of Single Case Study and Multiple Case Study Research Designs

The Case Study Method: Definition And Variations

According to Yin (1981), a case study is “(a) a contemporary phenomenon in its real-life context, especially when (b) the boundaries between phenomenon and context are not clearly evident” (p. 59). In other words, a case study focuses on observing a unique situation that occurs (or occurred) in real life; and, the case study method is particularly appropriate when the situation cannot be defined apart from the context in which it occurs (as opposed to a randomized, controlled experiment). The case itself can range from something concrete (e.g., an individual person or organization) to something abstract, e.g., a relationship or idea (Creswell & Poth, 2018; Yin, 2009a).

Epistemological beliefs play an important role in identifying the case, developing research questions, and deciding how the case study will be designed. Researchers must begin the case study research process with an understanding of their epistemological beliefs, because this epistemological perspective will ultimately guide the focus and direction of the research (Bloomberg & Volpe, 2016; Creswell & Poth, 2018; Huff, 2009). In this chapter, we will focus on case studies that align with a positivist or, alternatively, constructivist viewpoint. As the reader will note in the different examples presented in this article, some case studies seek to draw objective, generalizable conclusions based on scientific approaches to data collection and data analysis. This is reflective of the positivistic epistemological approach to case study research (Phillips & Burbules, 2000; Yin, 2009a). The constructivist epistemological approach also seeks to draw conclusions, but this approach is transparent about the role of the researchers’ subjectivity in interpreting the data (Yazan, 2015).

Central to the positivistic approach is the idea that “there are social facts with an objective reality apart from the beliefs of individuals” (Firestone, 1987, p. 16, italics in original); hence, objectivity, validity, and generalizability are considered the essential tenets of positivism-oriented research (Crotty, 1998). This leads those adopting positivism to believe that construct validity, internal validity, external validity (i.e., generalizability of the findings), and reliability should be emphasized in case study research (Yin, 2012b, 2018).

As opposed to Yin who has more quantitative or positivistic leanings, most contemporary case study researchers hold that constructivism should be the epistemology orienting and informing case study research (e.g., Merriam, 1998; Stake, 1995; Yazan, 2015) because, as Merriam (1998) elucidates, “the primary instrument in qualitative research is human, all observations and analyses are filtered through that human being’s worldview, values, and perspective” (p. 22). From the constructivist viewpoint, “knowledge is constructed rather than discovered. The world we know is a particularly human construction” (Stake, 1995, pp. 99-100), and, to use Merriam’s (1998) words, “reality is not an objective entity; rather, there are multiple interpretations of reality” (p. 23). Consequently, case study researchers with constructivist tendencies are interested in exploring and grasping the meaning people have constructed through their lived experiences with the world (Merriam, 1998) rather than trying to obtain objective, quantifiable, and generalizable knowledge as those with a positivistic orientation usually do (Crotty, 1998). That is, constructivist case study inquirers do not separate the phenomenon under study from its setting, for it is impossible to study a phenomenon void of its context (Miles & Huberman, 1994).

It is also significant to highlight how case study research tends to begin with a theoretical framework, in contrast to other methodological approaches, such as grounded theory (Merriam, 1985, Yin 2009b). Grounded theory research uses the data and experiences of participants to develop a theory, while case study research begins by identifying a theory to guide choices related to the data sources, data collection, and data analysis.