Interleaved practice provided near immunity against forgetting over a 30-fold increase in test delay¶

Claim · All claims
Evidence · 1 study · causal r2 · q3
Currency · newest study 2015 · not yet checked against its sources · not reviewed by a person

Subclaims¶

q3 i? For interleaved-practice material, increasing the test delay from 1 to 30 days reduced scores only slightly (80% to 74%). → Rohrer 2015

Evidence¶

Rohrer 2015¶

Rohrer, D., Dedrick, R. F., & Stershic, S. (2015). Interleaved practice improves mathematics learning. Journal of Educational Psychology, 107(3), 900-908. https://doi.org/10.1037/edu0000001

q3 · i? · causal · r2

Authors' descriptive comparison of interleaved-condition test means across the two delays in the classroom experiment. Only the printed means (80% vs. 74%) support this; no test of the within-condition delay effect is quoted.

"apart from its superiority to blocked practice, interleaved practice provided near immunity against forgetting, as the 30-fold increase in test delay reduced test scores by less than a tenth (from 80% to 74%)."

Discussion¶

Related Claims¶

• At a 1-day test delay, interleaved practice yields a moderate benefit over blocked practice (d = 0.42) — related
• Interleaved practice produces higher mathematics test scores than blocked practice in a classroom experiment — related
• The test benefit of interleaved practice does not diminish over time and perhaps grows larger (d = 0.79 at 30 days) — related
• The interleaving benefit appears in three of four problem-type-by-delay comparisons; the slope-problem effect at 1 day was not statistically significant — related
• The interleaving benefit is not caused by spacing, and the benefit extends to delayed tests — a broader claim this one bears on
• Interleaved practice improves delayed posttest performance compared with blocked practice — related