Spaced repetition
Spaced repetition is the practice of revisiting material at increasing intervals over time. It produces stronger long-term memory than the same amount of study done in one block.
- Subject
- Cross-curricular
- Key stage
- All
Hermann Ebbinghaus drew the forgetting curve in 1885. A century of follow-up research has confirmed his core finding: memory drops fast at first, then slowly, and well-timed reviews flatten the curve.
What it is
A study schedule where material is revisited at increasing gaps. A topic taught on Monday is reviewed Friday, then a fortnight later, then a month later. Each review costs less time than the original lesson but produces a disproportionate gain in retention.
Why it works
Cepeda and colleagues’ 2006 meta-analysis pulled together 254 studies and found a robust spacing effect across age groups, subjects, and retention intervals. Dunlosky’s review rates distributed practice as one of the two highest-utility strategies. The EEF cognitive science review puts it alongside retrieval as the most strongly evidenced techniques.
The mechanism is partly that retrieval at the edge of forgetting is harder, and harder retrieval strengthens the trace more than easy retrieval does.
How to use it
Build a do-now starter that includes one question from last lesson, one from last week, and one from last term. Use a knowledge organiser as the source. Set short homework tasks that revisit topics from earlier in the year, not just the current unit. Plan end-of-half-term review sessions that touch every topic taught since September.
The Chalk Retrieval Task tool generates spaced tasks across a unit if you give it the curriculum sequence.
When not to use it
Spacing assumes pupils have learnt the material to a baseline competence first. Spacing a topic that has not yet been understood just spreads the confusion out across more lessons.
Related Chalk tools
Retrieval Task and Worksheet Creator both support a regular spaced review routine. Visual Keywords can act as the retrieval cues for spaced quizzes.
Evidence
The spacing effect is one of the most replicated findings in memory research, from Ebbinghaus 1885 through Cepeda's 254-study meta-analysis. Classroom translation has been weaker than the lab work but converging applied studies confirm the principle. Pairs with retrieval practice as the highest-utility pedagogy in the Dunlosky review.
Try this in Chalk
Related concepts
Questions teachers ask
How big should the gaps be?
Is spaced repetition the same as retrieval practice?
Will spaced repetition look like I am repeating myself?
Retrieval Task
Low-stakes recall task with icons and keywords for spaced practice across a unit.
Open Retrieval Task