Peer-reviewed research
A meta-analytic review of the distribution of practice effect: Now you see it, now you don't
John J. Donovan and David J. Radosevich, Journal of Applied Psychology, 1999
Read the originalRead on October 16, 2026
- What it is
- A meta-analysis that pooled studies comparing spaced practice with massed practice. Across the pooled studies, spaced practice produced a mean weighted effect size of 0.46 in its favor, and the review reports that study conditions moderated the effect.
- How much weight it carries
- Peer-reviewed meta-analysis in a major applied psychology journal. The pooled studies cover many kinds of task, the review itself notes that the effect does not appear in every study, and the copy used here is a public PDF mirror of the article.
Facts taken from this source
- A meta-analysis of practice studies found that spaced practice beat massed practice, with a mean weighted effect size of 0.46 in favor of spaced practice.
“0.46, indicating that individuals in spaced practice conditions performed significantly higher than those in massed practice conditions.” (Results)