Recent advances in the cognitive psychology of inference have been of great interest to philosophers of science. The present paper reviews one such area, namely studies based upon Wason's 4-card selection task. It is argued that interpretation of the results of the experiments is complex, because a variety of inference strategies may be used by subjects to select evidence needed to confirm or disconfirm a hypothesis. Empirical evidence suggests that which strategy is used depends in part on the semantic, syntactic, (...) and pragmatic context of the inference problem at hand. Since the factors of importance are also present in real-world science, and similarly complicate its interpretation, the selection task, though it does not present a quick fix, represents a kind of microcosm of great utility for the understanding of science. Several studies which have examined selection strategies in more complex problem-solving environments are also reviewed, in an attempt to determine the limits of generalizability of the simpler selection tasks. Certain interpretational misuses of laboratory research are described, and a claim made that the issue of whether or not scientists are rational should be approached by philosophers and psychologists with appropriate respect for the complexities of the issue. (shrink)