# Evidence · Spaced Learning Practice

Evidence supports pilots, not universal promises. Classroom meta-analysis: **d = 0.54** with heterogeneity.

## Cases

| Case | Finding | Response |
|---|---|---|
| Classroom meta-analysis | d = 0.54 | Justify pilot, not guaranteed uplift |
| EEF SMART Spaces | Chemistry effect −0.01; high engagement, no attainment gain | Test the whole intervention |
| Primary-school study | Retrieval > rereading; spacing intervals ≈ (44.6% vs 45.9%) | Invest in questions/feedback first |
| Microsurgery RCT | At one month: 31.60 vs 27.63, p = 0.04 | Equalise hours; measure delayed |

## Claim / do not claim

**Claim:** spaced recall/application can improve later performance on average; delayed follow-up beats satisfaction; paid pilot with measurement agreement is the entry.

**Do not claim:** universal forgetting curve; guaranteed ROI; quiz accuracy = compliant behaviour; vendor marketing figures as science.

[Measurement](/spaced-learning-practice/measurement/)