A problem solving experiment is described where the difficulty Ss experienced in solving a panicular puzzle is manipulated using a dual task paradigm. Although Ss show impaired performance solving the puzzle the first time, performance improves considerably on a second trial and Ss are not impaired by a second trial memory load. In spite of the improvement in performance, Ss are unable to report virtually any information about the problem or their solution strategies. A model is presented that describes the pattern of performance across the levels of memory load and across the two trials. The theoretical implications of this model are discussed.
