Prior knowledge and memory: the influence of natural category size as a function of intention and distraction.

Words having larger numbers of related associates are more difficult to recall under conditions of intentional learning. This finding indicates that memory performance is inversely related to natural category size. The purpose of the experiments presented in this article was to evaluate the potential influence of orienting task and attention shifts associated with delayed testing on the natural category size effect. The results of Experiments 1 and 2 indicate that it is obtained regardless of task orientation. However, the results of Experiments 2 and 3 indicate that the effect is easily disrupted. Even after only 5 min of solving multiplication problems, words having larger sets of associates are no more difficult to recall than those having smaller sets. These findings suggest that related associates are automatically activated and encoded whenever a familiar concept is experienced in the absence of specific semantic cues. However, words having larger sets will be more difficult to recall only when these related associates are in a state of current activation.