SUMMARY KNOWLEDGE OF RESULTS FOR SKILL ACQUISITION - BEYOND LAVERY AND SCHMIDT

KR involves the presentation of KR, usually via a graph of performance over a prescribed set of trials, following the last trial of each set. Some evidence suggests that summary KR produces more perceptual-motor learning than presenting KR on every trial (Lavery 1962: Schmidt, Young, Swinnen and Shapiro 1989). Using a ballistic timing task, experiment 1 was a replication of Schmidt et al. (1989). Four KR summary conditions were employed 1-, 5-, 10-, and 15-trial summary conditions. The results, although not replicating the previous study, provided some support for the idea of an optimal summary length. During block 1 of the transfer (no KR) trials the 5-trial condition produced less error than the other conditions, even though the condition receiving KR on every trial had been most accurate during the acquisition (KR) trials. This 'summary effect' (i.e., reversal of the order of conditions from acquisition to transfer/retention favouring summary conditions during no-KR trials) was investigated further in experiment 2. Besides the 1-, 5-, and 10-trial conditions, a fourth group was added (10/5) which received summary information every 5 trials (a temporal delay equal to the 5-trial condition), but with a summary of 10 trials (an amount of summary information equal to the 10-trial condition). Although a 'summary effect' per se was not obtained, the 10/5-trial condition was more accurate than the other groups during the retention phase. These results indicated that the notion of summary KR is a multifactorial phenomenon.