These methods usually examine and interpret patterns in written or textual data. An explanatory case attempts to identify a causal relation between the context and the behavior. Use a case study to investigate a research question in which the subject of the study and the context of the study are intertwined. See disclaimer.

Case studies, as a research design, are also being conducted across disciplines and research traditions. The types of interviews conducted by researchers vary in degree of formality (informal interview to semi-structured to structured interviews). Doing Qualitative Research (2nd edition, pp. Selecting an appropriate case study design depends on the research question, and the research question dictates the data collection method or methods.

"Case Study The Method." Boston, MA: Jones and Bartlett Publishers. Thousand Oaks, CA. (1999).