Instrumental Case Study

Instrumental case study is a qualitative research design, formalised by Robert E. Stake (1995), in which a specific case is studied primarily to gain insight into an external issue or theoretical question — not because the case itself is intrinsically important. The case serves as an instrument for understanding something broader: a policy problem, a theoretical proposition, or a generalised phenomenon. One or several cases are selected because they are expected to illuminate the issue particularly well, and the researcher moves fluidly between the case and the issue throughout the study.