The Effects of Rule Clarification, Decision Justification, and Selection Instruction on Wason's Abstract Selection Task

The four card selection task was first described by Wason (1966) who can hardly have suspected that in the next quarter of a century it would become the most intensively researched single problem in the history of the psychology of reasoning. At the time of writing, there is no sign that interest in this task is abating, and submissions of papers on the problem to learned journals continue with great regularity (Evans, Newstead, & Byrne, 1993, p. 99).