Summary Knowledge of Results Effect

The summary knowledge of results effect is a finding in motor skill learning research in which providing knowledge of results only as a single combined summary covering several practice attempts at once, rather than immediately after each individual attempt, produces better long-term retention of a motor skill than trial-by-trial feedback, again despite the learner receiving less immediate feedback overall across the practice session. As with the bandwidth knowledge of results effect documented elsewhere in this section, researchers interpret the finding within the broader guidance hypothesis: delaying and combining feedback across several attempts is thought to reduce a learner's moment-to-moment reliance on externally supplied correction and to encourage the learner's own internal error-detection processes to develop instead, an effect that becomes especially pronounced once the number of attempts summarized together grows large enough that a learner can no longer simply hold every individual attempt's specific outcome in mind and effectively receives one combined, generalized piece of information rather than several precise ones. Together with the bandwidth effect, the summary knowledge of results effect is among the most frequently cited demonstrations in motor-learning textbooks that reducing the frequency or precision of feedback during practice can improve, rather than harm, how well a skill is retained once that feedback is removed.