Distinguish massed repetition from practice distributed over time.
Well supportedSeveral studies or meta-analyses point the same way.
Example
Editorial example: offer an optional short review days later rather than repeated reading in one session.
Why it works
Cepeda and colleagues synthesize verbal-memory studies, examining spacing in relation to the intended retention interval.
On the web
Select the target knowledge and offer later practice. Compare retention after equal delays rather than counting notification opens.
When it backfires
Findings mainly concern memory tasks, not visits or revenue. There is no single optimal schedule for every user.
Sources
Synthesizes distributed-practice research and examines spacing and retention intervals.
Cepeda, N. J., et al. (2006). Distributed practice in verbal recall tasks. Psychological Bulletin, 132, 354–380. Open source