Accounts of learning and generalization typically focus on factors related to lasting changes in representation (i.e., long-term memory). The authors present evidence that shorter term effects also play a critical role in determining performance and that these recency effects can be subdivided into perceptual and decisional components.…

Four experiments were conducted to determine the source of difficulty of Wason's THOG problem. The THOG problem permits examination of the way people tackle a novel hypothetico-deductive problem. The results are interpreted as demonstrating the importance of problem presentation in problem solving. (Author/PN)