Comparisons of Incidental and Intentional Learning after Different Numbers of Stimulus Presentations

Abstract

In a recent paper by Neimark and Saltzman it was found that the difference between the scores of incidental and intentional learning depends on the rate of presentation of the learning material.1 After four presentations of a list of 14 numbers where each number appeared for 2 sec., no difference was found between the scores of incidental and intentional learning. When, however, the numbers were presented at a slower rate of 6 sec. per number, the scores of intentional learning were significantly higher than those of incidental learning. While the scores of the incidental learners did not change significantly from the fast rate to the slow rate, the scores of the intentional learners, on the other hand, increased significantly. A similar relationship might be expected when the length of the time of exposure is held constant, but the number of exposures per item is increased. Specifically, one might expect that after only a few presentations of a list of numbers, no difference would be found between the scores of intentional and incidental learning, but that after many presentations of the list, a difference would be found. The present study was designed to investigate this relationship between the number of trials, on the one hand, and the difference between incidental and intentional learning scores, on the other. Procedure. The Ss were 160 Indiana University undergraduate students randomly divided into two groups of 80 each-an incidental learning group and an intentional learning group. Each group was further divided into four subgroups of 20 Ss each. The learning material was a list of 14 two-digit numbers selected from a table of random numbers. A different number of presentations of the list was given each of the subgroups. The subgroups in each group received either 2, 6, 8, or 16 presentations of the list. The rate of presentation of the list of numbers was the same for all subgroups: each number appeared for 3 sec. and then was replaced by the next number. The numbers were presented by means of an electrically operated memorydrum. A 10-sec. period intervened between successive presentations of the list. Four different random orders of the 14 numbers were used. The Ss in the incidental learning group were read the following instructions.