Abstract

This paper discusses alternative ways of defining and measuring institutional, pragmatic, empirical, and cognitive success in science. Four realist measures of epistemic credit are compared: posterior probability, confirmation (corroboration), expected verisimilitude, and probable verisimilitude. Laudan's non-realist concept of the empirical problem-solving effectiveness of a theory is found to be similar to Hempel's notion of systematic power. It is argued that such truth-independent concepts alone are insufficient and inadequate to characterize cognitive success. But if they are used as truth-dependent epistemic utilities, they serve as fallible indicators of the truth or truthlikeness of a theory.