Spaced Practice vs. Cramming: A Side-by-Side Comparison
For remembering over days and weeks, studies tend to favor spaced practice over cramming. For a test that is only hours away, we think cramming can be a reasonable emergency move. This article compares the two side by side, shows what the studies found, and gives you a fair plan if you only have two days.
Two terms first. Cramming, also called massed practice, means putting all your study into one block. Spaced practice, also called distributed practice, means spreading it over several sessions with gaps between them.
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What the studies found
A major review of study techniques rated distributed practice as high utility (Dunlosky et al., 2013). A short review of spacing research states that final-test performance improves when study sessions are spaced apart in time rather than massed in immediate succession (Carpenter et al., 2012).
In one experiment with college students, math practice spread over multiple sessions led to much better performance one week later than practice massed in a single session (Rohrer and Taylor, 2007). That was a laboratory study with specific kinds of math problems, tested after one week.
A meta-analysis of verbal recall tasks found that the best gap between sessions grew as the time until the final test grew (Cepeda et al., 2006). Read the other way, a test that is very close favors short gaps. That is our reading, and it is why cramming is not always foolish.
Feelings can mislead. In a study with paintings, participants rated massed study as more effective than spaced study, even after their own test results showed the opposite (Kornell and Bjork, 2008). Mixing different artists' paintings counted as spacing in that task, and it was a laboratory study, so do not transfer it directly to other materials. Still, a smooth, confident session does not by itself show that the material will last.
Spaced practice and cramming side by side
| Question | Cramming (massed) | Spaced practice |
|---|---|---|
| Shape | One or two long blocks right before the test. | Several shorter sessions with gaps between them. |
| Fits best when | The test is hours or a day or two away (our judgment). | The test is more than a few days away (our judgment). |
| How it feels | Often smooth and confident (our judgment). In one painting study, people rated massed study as more effective (Kornell and Bjork, 2008). | Harder and slower, with gaps you can see. |
| A week later, in one math experiment | Much worse performance when practice was massed in one session (Rohrer and Taylor, 2007). | Much better performance. |
| Main risk | Little time left to find and fix gaps (our judgment). | It needs planning and regular time (our judgment). |
When cramming is a reasonable move
If the test is tomorrow and you have not started, spreading study over weeks is no longer possible. Short gaps are the best you can do, so make them count. Be clear about what that likely buys: material that is fresh for a near test, which is our reading rather than a finding. In the experiment with a one-week delay, spaced practice came out ahead, so do not count on the material still being there next week. No study we cite tested cramming the night before a real exam.
Why material fades with time is covered in the forgetting curve explained.
A fair plan if you only have two days
- Day 1, first block. Sort your material into must-know and nice-to-know. Turn the must-know items into questions or cards.
- Day 1, second block, a few hours later. Answer the questions from memory, then check. Mark the misses. Do not reread everything.
- Day 1, evening. Quiz only the misses again.
- Day 2, morning. Answer the full set once more, then the misses again.
- Day 2, before the test. Skim only your marked misses. Stop adding new material.
This plan is our suggestion and has not been tested. It rests on two ideas from the sources: short gaps suit a short delay (Cepeda et al., 2006), and practice testing was rated higher than rereading (Dunlosky et al., 2013). The step of answering before you look is explained in the active recall guide.
After the test, keep your cards if you need the material later. What spaced repetition is and how to choose spacing intervals show how to space your reviews over time. For a longer runway, see a four-week retention plan before an exam, or practice spacing terms in Practice.
Common mistakes
- Spreading out rereading and calling it spaced practice. Add recall attempts to every session. The Dunlosky review rated rereading low utility and practice testing high (Dunlosky et al., 2013).
- Judging a session by how confident it feels. Participants in one study rated massed study as more effective even after their own results showed the opposite (Kornell and Bjork, 2008). Check yourself with a closed-book quiz.
- Starting spaced practice the night before. Spacing needs days. Start as early as you can, even if you only fit in two or three sessions.
- Cramming everything instead of the must-know items. Rank your material first. With little time, spend it on what the test will most likely ask.
Frequently asked questions
Is cramming ever a good idea?
It can be a reasonable last resort when the test is hours or a day or two away, since short gaps suit a short delay. It is a weaker plan for anything you need next week, because in one math experiment spaced practice did much better on a test one week later (Rohrer and Taylor, 2007).
Can I combine spacing and cramming?
Yes. Do what you can in spaced sessions, then use the last day or two for a focused review of the items you missed. This is practical advice rather than a tested plan.
How far ahead should I start?
As early as your calendar allows. The best gap tended to grow with the delay until the test (Cepeda et al., 2006), so an early start lets you use longer gaps. None of the sources we read gives a minimum number of days.
Does this mean cramming does not work at all?
No. The studies we cite compared spaced and massed practice on later tests, and spaced practice tended to come out ahead. They do not show that massed study teaches nothing. Results also vary between people and between kinds of material, so treat the comparison as a tendency, not a rule.
Sources
We opened each source below before citing it. See Methodology and Sources for how we check them.
- Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving Students' Learning With Effective Learning Techniques: Promising Directions From Cognitive and Educational Psychology. Psychological Science in the Public Interest, 14(1), 4-58. Open the source
- Carpenter, S. K., Cepeda, N. J., Rohrer, D., Kang, S. H. K., & Pashler, H. (2012). Using Spacing to Enhance Diverse Forms of Learning: Review of Recent Research and Implications for Instruction. Educational Psychology Review, 24(3), 369-378. Open the source
- Rohrer, D., & Taylor, K. (2007). The shuffling of mathematics problems improves learning. Instructional Science, 35(6), 481-498. Open the source
- Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin, 132(3), 354-380. Open the source
- Kornell, N., & Bjork, R. A. (2008). Learning concepts and categories: Is spacing the 'enemy of induction'?. Psychological Science, 19(6), 585-592. Open the source
This guide is general study help, not medical or professional advice. It was last reviewed on November 12, 2026. Spot a mistake? Tell us here.