The spacing benefit holds even at very short retention intervals, contradicting the Peterson paradox¶

Claim · All claims
Evidence · 1 study · quant-synthesis r2 · q2
Currency · newest study 2006 · checked against its sources 2026-10-18 (automated, 1 of 1 entry) · not reviewed by a person

Subclaims¶

q2 i? Spaced presentations outperformed massed presentations even when the retention interval was less than 1 min, contrary to claims of a massing benefit at short retention intervals. → Cepeda 2006

Evidence¶

Cepeda 2006¶

Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed Practice in Verbal Recall Tasks: A Review and Quantitative Synthesis. Psychological Bulletin, 132(3), 354-380. https://doi.org/10.1037/0033-2909.132.3.354

q2 · i? · quant-synthesis · r2

Meta-analytic comparison collapsing massed-versus-spaced differences over seven retention interval ranges (Table 1). At retention intervals under 1 min, spaced exceeded massed 50.1% vs. 41.2% correct, t(208) = 3.7, p < .001. The article notes purported massing benefits may occur only at retention intervals of 2-8 s.

"there is no hint that massed presentation was preferable to spaced, whether retention interval was very short (less than 1 min) or very long (over 30 days)"

Discussion¶

Learner Variables¶

• Long-Term Memory — outcome: instruction changes it

Related Claims¶

• Spaced presentations produce markedly better final recall than massed presentations across retention intervals — a broader claim this one bears on
• With incidental orienting tasks that focus processing on individual words and give no incentive to form associations, distributed presentations produce better free recall than massed presentations — a narrower finding that bears on this claim
• ISI effects on recall are nonmonotonic and depend jointly on retention interval — related
• Recall of words repeated across lists spaced up to 1 week follows a proportionality rule: recall is better after short spacing at short retention intervals but better after long spacing at long retention intervals — reports the opposite
• Spacing out retrieval practice produces better long-term retention than massing it — related