Facilitation in short- and long-term retention of paired associates following distributed practice in learning

Abstract

Summary Four experiments tested an hypothesis offered by Underwood, et al. (1962) which states that distributed practice (DP) given during the learning of the last in a series of A-B, A-C, A-D, A-E lists allows for greater extinction of prior associations from the first three lists, resulting in higher retention when the last list is learned under DP than under massed practice (MP). For the first three experiments, DP was administered on the last list and consisted of three 24-hour intervals interpolated between pairs of trials. In Exps. 1 and 1a, the four lists formed an A-C paradigm, while in Exp. 2 the lists formed an A-Br paradigm, where the lists consisted of four successive pairings of stimulus and response terms. In Exp. 1 retention was taken after 1 and 8 days, in Exp. 1a, after 29 days, for DP only, and in Exp. 2, after 8 days. In Exp. 3, the short-term retention of the last in a series of single paired associates, forming an A-B, A-C, etc. paradigm, was studied. Retention was taken either 30 or 90 sec following the final presentation of the last pair; the interval between successive presentations of the last pair was either 4 1/2 sec (MP) or 33 sec (DP). Retention of List 4 after 1 day was 89 and 31% and after 8 days, 72 and 7% for the DP and MP groups, respectively, in Exp. 1; and after 29 days, 34% for the DP group in Exp. 1a. These results indicate marked superiority in the retention of List 4 following learning under DP. In Exp. 2, employing the A-Br paradigm, the DP effect, defined in terms of the difference in retention loss for the DP and MP groups, was 2.58 items, this difference being half that obtained for the same conditions in Exp. 1 for the A-C paradigm (5.11 items). These results required the modification of the theory of Underwood et al. to include the forward and backward associations under conditions of widely spaced DP intervals. In Exp. 3, after both retention intervals, retention was superior for the DP condition. The results of this experiment extend the applicability of the extinction-recovery theory to the short-term retention of single paired associates.