Multiple case-based case study

A multiple case study (also called a multiple-case design or collective case study) is a qualitative research design in which two or more bounded cases are examined together to pursue a common research question. By studying several instances of a phenomenon in parallel, the researcher can compare patterns, identify convergences and divergences, and build more robust, transferable conclusions than a single case could support. The design draws principally from Robert Yin's case-study methodology and Robert Stake's collective case study tradition.