Types of case study work: A conceptual framework for case-based research

This article describes a conceptual framework for understanding the phases of case-based research. Case-based strategies in research are widely used in case study methodology as well as in a number of qualitative methodologies, including grounded theory development, phenomenological research method, and psychotherapy process research. The epistemological principles on which case-based research is based are fundamentally different from those that inform group-based research using quantitative multivariate statistics. The case-based research process is divided into three general phases: descriptive, theoretical-heuristic, and theory testing. Each of these phases is subdivided into two categories. The aims and epistemological principles related to each phase are discussed and illustrated with examples from contemporary research. The principles for establishing validity in case-based research are also reviewed and, to assist research students and supervisors, some common pitfalls are noted. The article shows that rigorous work with single cases or series of cases using case-based principles and methodology is indeed, as Bromley claimed, "the bedrock of scientific investigation."