Effects of prior knowledge on use of cognitive capacity in three complex cognitive tasks.

Prior knowledge was varied in problem solving, thinking, and reading tasks in three experiments. The hypothesis was that the prior knowledge used in a cognitive task uses capacity in the same limited capacity active processing system that is used to process the ongoing task. In a reading experiment, prior knowledge about a target page was manipulated by controlling the preceding pages. In an experiment dealing with problem solving in the context of a chess game, prior knowledge was controlled by comparing experts with novices. In a third study subjects thought about personality descriptions of persons and groups, and about women's fashions and football plays; it was assumed that persons have more prior knowledge concerning the personality of persons than the personality of groups, that women have more prior knowledge about women's fashions, and that men have more prior knowledge about football. In all experiments, use of cognitive capacity in task performance was observed with a secondary task technique. The results of all three experiments were consistent with the hypothesis that prior knowledge uses capacity in the active processing system. The prior knowledge hypothesis is consistent with some aspects of current cognitive theory but not consistent with others. The results also suggest a fundamental and unexpected limit on the cognitive processing of experts.