REDUCED FREQUENCY OF KNOWLEDGE OF RESULTS ENHANCES MOTOR SKILL LEARNING

Relative frequency of knowledge of results (KR) is the proportion of KR presentations to the total number of practice trials. Contrary to predictions from most traditional motor learning perspectives (e.g., Adams, 1971; Schmidt, 1975; Thorndike, 1927), recent evidence suggests that, compared with practice in 100% relative frequency conditions, practice with lower relative frequencies may be beneficial to longer-term retention and learning, but detrimental to practice performance. Three experiments are reported in which the effects of variations in acquisition KR relative frequency were examined. Experiment 1 showed that a markedly reduced KR relative frequency during practice was as effective for learning as measured by various retention tests, compared with a 100% KR practice condition. In Experiments 2 and 3, when the scheduling of KR was manipulated so that the number of KR trials was systematically lowered across practice, a reduced average relative frequency enhanced learning as measured by a delayed no-KR retention test (Experiment 2) and a retention test in which KR was provided (Experiment 3). Results are inconsistent with predictions from an acquisition-test specificity hypothesis and conventional motor learning theories and thus suggest a revision in the principles governing the role of KR for motor learning. Empirical support is provided for the KR guidance hypothesis (Salmoni, Schmidt, & Walter, 1984) and for various encoding-retrieval operations associated with spaced retrieval practice. Possible learning strategies invoked by relative frequency and other related practice variations are discussed with respect to response consistency and the development of intrinsic error detection mechanisms.