Problematic tools: Introduction to symposium on set theory in social science

Analysts who developed the set-theoretic comparative method (STCM) have formulated admirable goals for researchers who work in the qualitative and multi-method tradition. This method includes above all Charles Ragin’s innovative approach of Qualitative Comparative Analysis (QCA), along with further systematization of the set-theoretic framework by other au-thors.1 These colleagues are outstanding scholars and intel-lectual leaders in the field of methodology, and their advocacy of these goals is a major contribution.