This paper revisits Daniel Kahneman and Amos Tversky’s work on ‘framing’. It shows how various conventions from economic theory allow the establishment of different equivalence relations between pairs of problems in framing experiments. Then, an exegesis of their comments on these experiments is conducted regarding the relation between their theoretical explanation through prospect theory and the positive/normative distinction in models of individual behaviors. Throughout, a methodological framework with a distinction between identity, equivalence and equality (borrowed to philosopher Craig Dilworth) is developed for a critical analysis of the relation between external frames (the empirical structure of a decision problem) and internal frames (the psychological representation of the decision problem by decision makers).