Peer-reviewed research
Distributed practice in verbal recall tasks: A review and quantitative synthesis
Nicholas J. Cepeda et al., Psychological Bulletin, 2006
Read the originalRead on October 16, 2026
- What it is
- A meta-analysis of spaced versus massed practice in verbal recall experiments, covering 839 assessments from 317 experiments in 184 articles. It finds that the best gap between study sessions depends on how long the memory must last.
- How much weight it carries
- Peer-reviewed meta-analysis, widely cited, and the standard review of the spacing effect. It studies memorising words and facts, not dictation or motor skills. Any use for practice schedules is an application by analogy, and this guide says so.
Facts taken from this source
- A 2006 meta-analysis of distributed practice covered 839 assessments from 317 experiments in 184 articles.
“This review found 839 assessments of distributed practice in 317 experiments located in 184 articles.” (Abstract)
- In a 2006 review of verbal recall studies, the gap between study sessions that gave the best retention grew as the retention period grew.
“the ISI producing maximal retention increased as retention interval increased” (Abstract)