A case study is not a speciﬁc method but rather a research strategy (Yin 1981). Case studies investigate properties, actions, attitudes, and social structures of individuals, groups, or institutions by applying one or more methods, such as participant observation, interviews, and analysis of documents (Thomas 2010). Furthermore, case study research is characterized as an approach “that facilitates exploration of a phenomenon within its context using a variety of data sources” (Baxter and Jack 2008: 544). The philosophical background is a qualitative, constructivist paradigm, based on the claim that reality is socially constructed and can best be understood by exploring the tacit, i.e., experiencebased, knowledge of individuals. Therefore, immersion and empathy are necessary conditions for case study research (Hammersley and Gomm 2000: 1; Stake 2000: 21; Baxter and Jack 2008: 545). Case studies are distinguished from other major types of social inquiry, such as experiments and survey studies, by their explorative nature, their use of various methods, and their bottom-up procedures (Hammersley and Gomm 2000: 2). Although case studies aim at investigating a social phenomenon through
the lenses of the involved actors, they nevertheless require some kind of prior categorization of the phenomenon. The previous identiﬁcation and categorization of the phenomenon, or the case, distinguishes case studies from ethnographic research. There is always a broader, abstract, and more or less deﬁned category that is applied to a speciﬁc, individual phenomenon, or a group of related phenomena. One could, for example, study diﬀerent types of multilingual communication in German hospitals (i.e., categorized communicative practices) with reference to the concept of “inclusive multilingualism” (Backus et al. 2013). In this sense, “inclusive multilingualism” is taken as a deﬁned concept, and the speciﬁc forms of multilingual communication (i.e., code-switching, interpreting, and translation) are labels for observable phenomena. Taking the concept of “inclusive multilingualism” as an example, one could study one hospital or more than one, or compare hospitals with other public service institutions, or compare German hospitals with Dutch clinics. In either case, the concept and its underpinnings create theoretical expectations, by which categorized
phenomena are analyzed. Conversely, the concept itself is reﬂected and studied through the lenses of concrete and speciﬁc social phenomena, such as communicative practices in speciﬁc institutions. Thus, case studies do not have to be limited to individual cases. Rather, they may focus on a number of instances of a single case or even on diﬀerent, though interrelated, cases. Furthermore, cases can be studied over time, or in relation to a speciﬁc historical moment-i.e., researchers may focus on developmental aspects in longitudinal projects-or they may be interested in the “here and now” of a speciﬁc social phenomenon. Case studies aim at exploring a certain phenomenon or issue in depth. This
leads researchers to limit the number and size of the cases under investigation. Another limitation is that case study research focuses on naturally occurring data, and therefore control of variables is not a major concern. The generalizability of results and observations is limited, and the primary goal is to develop an understanding of the case, and not the testing of theory-driven claims. As case study data may come from a variety of sources, case studies are
often, but not necessarily, based on diﬀerent methods (mixed methods) and, as a consequence, diﬀerent data sources. Yin (2012: 10) lists the following six common data sources: direct observations, interviews, archival records, documents, participant observation, and physical artifacts. For Translation and Interpreting Studies, additional sources may include source and target texts or transcriptions of authentic discourse (Meyer 1998).