MOTOR SKILL ACQUISITION AND RETENTION AS A FUNCTION OF AVERAGE FEEDBACK, SUMMARY FEEDBACK, AND PERFORMANCE VARIABILITY

Summary feedback involves withholding feedback from subjects until the last trial in a block is completed, and then presenting feedback abou t each trial. A variation of this method, called average feedback (You ng & Schmidt, 1992), presents subjects with only the mean of the trial block. We investigated whether these methods have similar effects on acquisition and retention of a simple motor skill. Five groups of subj ects (n = 16 per group) performed 60 acquisition trials of an aiming t ask involving both spatial and temporal accuracy. We presented average and summary feedback based on either 5-trial blocks or 15-trial block s and compared these schedules with every-trial feedback. During acqui sition, all groups improved with practice, with a slight tendency for the every-trial condition to have less absolute error than the longer summary and average conditions. Analysis of delayed no-feedback retent ion tests, however, revealed a strong advantage for the 5-trial summar y and average conditions compared with the every-trial condition. In a ddition, we found that for long blocks of acquisition trials without a ugmented feedback, the performance variability of those trials was ass ociated with retention performance. Results are discussed in terms of how these different manipulations may make feedback less useful during acquisition, but foster the use of certain information processing act ivities that enhance overall learning.