Spaced practice

What it is

Spaced practice, also called distributed practice, means returning to the same material on more than one occasion, with time between them. In a course that looks like cumulative quiz items, a short review of older topics at the start of class, or problem sets that revisit earlier units.

Cramming can work for a test tomorrow. Spacing works for a test next month. A meta-analysis of distributed practice summarized 839 assessments from 317 experiments in 184 articles and found that the gap between study sessions and the time until the test work together to determine how much is remembered.¹

Evidence and fit at a glance

Strong evidence

Decades of controlled experiments agree that spacing beats massing for long-term retention. Much of the evidence on the best gap comes from studies that taught facts, so treat the exact timing as a rough guide for other kinds of learning.

How evidence is labeled

Set-upA few hours to map which ideas return when. After that it is mostly re-ordering work you already have.
Class timeMostly no added class time: older items move into quizzes, openers, and later problem sets.
DeliveryIn person, Live online, Self-paced online
Class sizeAny class size
AI roleWorks with or without AI

When it works, and when it doesn’t

Best when

The course is cumulative and students must remember early material for a final or a later course.
You meet students many times over a term, so reviewing is cheap to add.
You can build review into work students already do: cumulative quiz items, older problems on new problem sets.
You know roughly how long students need to remember the material (weeks or a year), which sets how far apart to space it.

Weak when

The course or workshop is a single session. There is no later occasion to return to the material.
The material is brand new and not yet understood. Spacing strengthens memory of what was learned. It does not replace teaching it first.
Review is added with no time removed, so new content gets squeezed. Cutting a little new material to make room is usually part of the trade.
Gaps are so long that students have forgotten nearly everything before the next encounter. Past a point, longer gaps reduced performance in the study described below.²

How to do it

List what must last.Mark the 10 to 20 ideas, procedures, or terms students must still know at the final or in the next course.
Plan at least three encounters.First teaching, a return within about a week, and another a few weeks later. Add more returns for the most important items. This is a practical starting rule, not a research threshold.
Match the gap to the finish line.In one large study the best gap was about 20 to 40% of a one-week test delay, and 5 to 10% of a one-year delay.² Use that as a rough guide: for a final a couple of months away, gaps of a week or more are reasonable.
Build the returns into existing work.Put older items on quizzes, start-of-class retrieval questions, and later problem sets.
Bring back what slipped.Use quiz results to find items students missed, and return to those sooner.

With AI and without

Without AI

No AI is needed. A list of outcomes by week is enough to plan the schedule.

With AI

AI can help draft the schedule and cumulative question sets from your outcomes list. Check every item for accuracy, and set the spacing yourself using the research above, because a chatbot's default plan may not fit your term length.

What the research says

What the studies found

A meta-analysis of distributed practice summarized 839 assessments from 317 experiments in 184 articles. It examined spacing, lag, and expanding intervals, and found that the gap between sessions and the retention interval jointly affect final-test retention.¹

A later study taught facts to more than 1,350 people, offered review after gaps of up to 3.5 months, and tested up to one year later. For a given delay before the test, longer gaps first improved performance and then reduced it. The best gap grew as the delay lengthened but shrank as a share of that delay, from about 20 to 40% of a one-week delay to 5 to 10% of a one-year delay.²

In math practice

In two experiments with 216 college students practicing one type of math problem, spreading 10 problems across two sessions a week apart made little difference for students tested after one week, but gave a very large benefit when they were tested four weeks later. Adding six extra problems in the same session (overlearning) did not improve scores at one or four weeks.³

Reviews for instructors

A policy-oriented review argues that scheduling review within existing instructional time is a low-cost way to improve learning, reports benefits for memory, problem solving, and transfer, and notes that adding tests to spaced practice strengthens the effect.⁴ A review of spacing across diverse forms of learning discusses implications for instruction.⁵ In a review of ten study techniques, distributed practice was rated high utility.⁶

Pedagogical justification, ready to paste

Use this in a lesson plan, syllabus, or course-design form. Replace the [bracketed] parts with your own course details. Check the claims against the references before you submit.

One-sentence version

Core ideas return in quizzes and problem sets at spaced intervals because distributed practice improves long-term retention compared with massed practice,¹ and in one math study spacing practice a week apart produced a very large benefit at a four-week test.³

Full rationale

Because the course is cumulative, core ideas are scheduled to return at spaced intervals rather than being taught once and tested once. Each important idea is taught, revisited in a low-stakes quiz or problem set within about a week, and revisited again several weeks later. This design follows a meta-analysis of 839 assessments from 317 experiments, which found that the gap between sessions and the time until the test jointly determine retention,¹ and a study of more than 1,350 learners showing that the best gap grows with the retention interval but shrinks as a proportion of it.² In a math study with 216 college students, practice spread across two sessions a week apart gave a very large benefit at a four-week test, while extra same-session practice did not.³ Review is built into existing assignments, so spacing adds little class time.

Learning outcome: Students will be able to [verb + core concept] at the end of the term, weeks after first learning it.
Evidence of learning: [Cumulative final items] on early-unit content, plus the share of students missing each returned item on later quizzes.
Learning activity: Each core idea appears in [first teaching], a review within about a week, and a second review several weeks later, built into existing quizzes and problem sets.

The copy buttons paste plain text. The pasted version renumbers the references from 1 and includes them with a source line, so it works on its own. The numbers shown here match the reference list below.

Limits of the evidence

Much of the best-gap evidence comes from studies that taught facts to adults. For procedures, concepts, and writing, treat the gap sizes as a rough guide.²
Most controlled studies end within a year of study. This page does not make claims about retention over several years.
Spacing is easy to describe and hard to fit into a crowded syllabus. Expect to trade some new content for review time.
This page does not cite a community-college-specific trial. Check your own cumulative-quiz data.

Questions faculty ask

How far apart should I space review?

It depends on how long students need to remember. In one study with more than 1,350 people, the best gap was about 20 to 40% of a one-week test delay and 5 to 10% of a one-year delay.² For a course, a return within about a week and another a few weeks later is a reasonable start.

Is spaced practice the same as interleaving?

No. Spacing is about time between encounters with the same material. Interleaving mixes different problem types within a session. They are often used together, but this page covers spacing only.

Does spacing take more class time?

Usually not. Older items move into existing quizzes, openers, and problem sets, though you may need to cut a little new material to make room.

References

Cepeda NJ, Pashler H, Vul E, Wixted JT, Rohrer D. Distributed practice in verbal recall tasks: a review and quantitative synthesis. Psychol Bull. 2006;132(3):354-380. doi:10.1037/0033-2909.132.3.354
Cepeda NJ, Vul E, Rohrer D, Wixted JT, Pashler H. Spacing effects in learning: a temporal ridgeline of optimal retention. Psychol Sci. 2008;19(11):1095-1102. doi:10.1111/j.1467-9280.2008.02209.x
Rohrer D, Taylor K. The effects of overlearning and distributed practise on the retention of mathematics knowledge. Appl Cogn Psychol. 2006;20(9):1209-1224. doi:10.1002/acp.1266
Kang SHK. Spaced repetition promotes efficient and effective learning: policy implications for instruction. Policy Insights Behav Brain Sci. 2016;3(1):12-19. doi:10.1177/2372732215624708
Carpenter SK, Cepeda NJ, Rohrer D, Kang SHK, Pashler H. Using spacing to enhance diverse forms of learning: review of recent research and implications for instruction. Educ Psychol Rev. 2012;24(3):369-378. doi:10.1007/s10648-012-9205-z
Dunlosky J, Rawson KA, Marsh EJ, Nathan MJ, Willingham DT. Improving students' learning with effective learning techniques: promising directions from cognitive and educational psychology. Psychol Sci Public Interest. 2013;14(1):4-58. doi:10.1177/1529100612453266

About this page

Written by Jesse Rogers, Learning Lab Coordinator, Palm Beach State College. Last updated October 15, 2026.

AI disclosure. Model used for research, drafting, editing, and verification: claude-sonnet-5-5 (Claude, by Anthropic). The author is responsible for every claim and citation.

How it was checked. Bibliographic details were checked against DOI records. Numbers and findings were checked against abstracts or open full texts. Where that was not possible, the page says so. See the method page.

License. CC BY 4.0. Share and adapt it with credit. This is an independent project and is not an official resource of Palm Beach State College.

Corrections. If you find an error, message me on LinkedIn and I will check it and fix it.

Cite this page (AMA). Rogers J. Spaced practice. Learn With Jesse. Published October 15, 2026. Updated October 15, 2026. Accessed [date]. https://learnwithjesse.com/techniques/spaced-practice/