Factual and modal notions in social research

The article discusses a distinction between factual and modal notions, and corresponding generalizations, in social research. The discussion starts from the suggestion, made by Charles Ragin, that theoretical statements in social research most often can be formulated as statements about sets of cases and relations between such sets. In contrast to this view, it is argued that theoretical statements in social research often require modal notions referring to possibilities and probabilities which cannot be formulated as statements about sets of cases. In order to show this, the article reformulates Ragin’s set-theoretic approach in the conceptual framework of statistical variables. It is shown that this can be done for both crisp and fuzzy set versions of Ragin’s approach. The article then goes on to argue that social research is often interested in modal generalizations (probabilistic and deterministic rules) which require a fundamentally different conceptual framework. The article shows how such a framework can be defined, and finally indicates its usage for causal interpretations.