Explanatory Case Study

Conceptual Overview and Discussion

Case studies are often lumped together under the rubric of qualitative research and are frequently confused with methods such as ethnography and grounded theory as well as those of quasiexperimental research. In fact, explanatory case studies are distinct from all of these, and unlike most qualitative research that is employed to explore certain phenomena, explanatory case studies can be employed to explain phenomena.

Explanatory case studies should consist of an accurate description of the facts of a case, considerations of alternative explanations, and a conclusion based on credible explanations that are congruent with the facts. A major proponent of using case studies to explain phenomena has been Robert Yin.

The central feature of any case study is the intense focus on a single phenomenon. In investigating this phenomenon, researchers must be concerned with all possible sources of data that may shed light on the phenomenon. Therefore, case studies should not be directly associated with any one type of data collection. Consequently, the design should be driven by the needs of the case study methodology, not by the requirements of any one type of data analysis. This is equally true in explanatory case studies.

The most difficult part of conducting any case study is defining the case. A case that isn't well defined can lead to findings that aren't actually about the case but rather something else entirely or, in the case of multiple case studies, that the individual cases are not in fact comparable. Using common terms to define a case can also be problematic in that investigators may understand different things by the same term. It is critical that investigators describe the case clearly in language that everyone understands to mean the same thing. Essentially, in order to develop an explanation the investigator needs a clear understanding of the phenomenon or phenomena under investigation. See for example G. T. Allison's classic study of the Cuban missile crises, where he very clearly defines the phenomena under investigation.

Application

Explanatory case studies should follow an outline that clearly indicates the priorities to be explored. Some type of flowchart or logic model that portrays the patterns to be investigated is necessary in order to ensure that the investigation stays on track. Completing such a logic model in advance of the start of the research can guide investigators as to what topics or questions need to be explored.

While following an outline is critical to the design of a case study, such forward thinking does not mean that the investigator is rigidly stuck following such an outline. A key feature of an explanatory case study is for the investigator to remain [Page 371]open to new discoveries during the process. Similar to a crime scene investigator using strict scientific methods in a crime scene investigation yet staying open to all possibilities affecting the crime, researchers using this method must also stay alert to all new possibilities. However, in order to prevent biasing a study by allowing such discoveries to modify the design, researchers may have to revisit the entire design should such a discovery call into question the earlier work. This iterative process is a strength of the explanatory case study as it ensures that the explanation is arrived at independent of any methodological biases.

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