Reduced Frequency of Knowledge of Results Enhances Motor Skill Learning
Winstein, C. J., & Schmidt, R. A. · 1990
grade Cquasi-experimentindependentfailed
Population
UCLA kinesiology undergraduates (Exp1 n=136; Exp2 n=58; Exp3 n=46); healthy young adults
Design
Three lab experiments, quasi-random assignment, researcher-designed arm-movement waveform-matching task scored as RMS error. Exp1: 8 groups n=17 (uniform reduced KR). Exp2: n=29/group, 50% FADED vs 100% KR, 5-min + 24-h no-KR retention. Exp3: n=23/group, 24-h retention WITH KR. Canonical guidance-hypothesis demo; no preregistration, no transfer test.
Key findings
Founding evidence for the guidance hypothesis: 100% KR flatters practice performance but breeds dependence; 50% faded KR gave 35% less error at 24-h no-KR retention and also beat 100% on a delayed KR retention test. Crucially the benefit was absent at 5-min retention and absent in Exp1 where reduced frequency was uniform, not faded — the effect depends on SCHEDULE, not frequency alone. Small n (~29/group), one artificial lab task, one lab.
Genetic confound
Randomized, so not confounded; but individual differences in feedback dependence are treated as error variance — no aptitude-treatment interaction modeled.
Replication notes
Cited as canonical, but the literature it spawned fails to confirm it in aggregate (McKay et al. 2022 frequency meta-analysis).
Effects
| Outcome | Metric | Value | Measure | Timing | Vs | Horizon | Class |
|---|---|---|---|---|---|---|---|
| Delayed 24-h no-KR retention (Exp 2) | RMS error, 50% faded KR vs 100% KR | 50% group 35% lower error; F(1,56)=6.24, p<.01 (d≈0.67, computed from F) | researcher-designed | retention; delayed 24h; lab | active-alternative | end-of-treatment | domain-skill |
| Immediate 5-min no-KR retention (Exp 2) | RMS error | 50% < 100% in same direction but NOT significant — benefit only emerges on the delayed test | researcher-designed | retention; immediate; lab | active-alternative | end-of-treatment | domain-skill |
| Acquisition performance (Exp 1) | RMS error during practice blocks | Reduced-KR groups performed WORSE than 100% KR, especially early practice (the paradox) | researcher-designed | acquisition; during practice; lab | active-alternative | end-of-treatment | domain-skill |
| Delayed 24-h retention WITH KR present (Exp 3) | RMS error | 50% group lower; F(1,44)=6.56, p<.02 (d≈0.77, computed) — not just test-specificity | researcher-designed | retention; delayed 24h; lab | active-alternative | end-of-treatment | domain-skill |
| Uniform (non-faded) reduced frequency (Exp 1) | RMS error across 4 retention conditions | Reduced ≈ 100% (no reliable benefit); advantage appeared only with a FADED schedule | researcher-designed | retention; delayed; lab | active-alternative | end-of-treatment | domain-skill |
Cited by
- Feedback frequency and mental practice in motor learningmixedconf: highgc: low