Case Studies Confusion: types of evidence (e.g., qualitative data) types of data collection methods (e.g., ethnography) research strategies (e.g., case studies) Goal of Case studied: establish the parameters which can be applied to all research. Thus, even a single case could be considered acceptable. Yin (2003), Case Study Research: Design and Methods. Yin (1981), âThe Case Study Crisis: Some Answers,â Administrative Science Quarterly, Vol. 26, No. 1, pp. 58-65.