The science of remembering
NoReread isn't built on a hunch. It implements the two study techniques that decades of cognitive-science research rate “high utility” — active recall and spaced repetition — and nothing it doesn't.
Recall with testing vs rereading
Active testing more than doubled recall compared to passively rereading the same material.
Karpicke & Roediger, Science, 319(5865), 966–968.[2]
More long-term retention
Retrieval practice beat even elaborate concept mapping for what sticks weeks later.
Karpicke & Blunt, Science, 331(6018), 772–775.[8]
The testing effect is real
A meta-analysis of 159 studies confirms a moderate-to-large effect size for practice testing.
Rowland, Psychological Bulletin, 140(6), 1432–1463.[7]
Abstract
Rereading is the most prevalent study strategy among university students (84%[1]), yet comprehensive reviews consistently rate it as having low utility for durable learning. In contrast, practice testing and distributed practiceare the only techniques rated “high utility” across hundreds of experiments.[1] NoReread implements the SM-2 spaced-repetition algorithm, combining both into a single tool. Converging evidence from multiple labs suggests this approach can roughly double long-term retention compared to rereading alone.[2]
Key findings
- 56% vs 40% — recall after one week for students who tested once, versus those who read the same passage four times. Psychological Science, 17(3), 249–255.[3]
- 90% — of participants learned more from spaced flashcards, yet a majority believed cramming was more effective. Applied Cognitive Psychology, 23(9), 1297–1317.[6]
- The forgetting curve — without review, memory of new material decays sharply within 24 hours; spaced reviews flatten the curve. Ebbinghaus, 1885.[4]
Table 1
Effectiveness ratings from Dunlosky et al., 2013[1]
| Technique | Rating |
|---|---|
| Practice testing (flashcards) | High |
| Distributed practice (spacing) | High |
| Interleaved practice | Moderate |
| Elaborative interrogation | Moderate |
| Rereading | Low |
| Highlighting | Low |
| Summarization | Low |
References
- Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students' learning with effective learning techniques. Psychological Science in the Public Interest, 14(1), 4–58.
- Karpicke, J. D., & Roediger, H. L. (2008). The critical importance of retrieval for learning. Science, 319(5865), 966–968.
- Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning. Psychological Science, 17(3), 249–255.
- Ebbinghaus, H. (1885). Über das Gedächtnis. Duncker & Humblot.
- Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., & Rohrer, D. (2006). Distributed practice in verbal recall tasks. Psychological Bulletin, 132(3), 354–380.
- Kornell, N. (2009). Optimising learning using flashcards. Applied Cognitive Psychology, 23(9), 1297–1317.
- Rowland, C. A. (2014). The effect of testing versus restudy on retention. Psychological Bulletin, 140(6), 1432–1463.
- Karpicke, J. D., & Blunt, J. R. (2011). Retrieval practice produces more learning than elaborative studying. Science, 331(6018), 772–775.
Common questions
Do flashcards actually work, or do they just feel productive?
They work — and they're one of the few methods that does. Practice testing (which is what a flashcard is) is rated 'high utility' in the most comprehensive review of study techniques, while rereading and highlighting are rated 'low'. The catch is that the effective methods feel harder, so most people abandon them for the ones that feel easy.
What is the testing effect?
The finding that retrieving information from memory — answering a question — strengthens that memory far more than re-reading the same information. Across 159 experiments the effect size is moderate-to-large (d ≈ 0.50). Every time you flip a card and try to recall the answer, you're using it.
What is spaced repetition?
Reviewing material at expanding intervals — a day, then a few days, then a week — instead of cramming it all at once. Distributing the same study time across days dramatically improves long-term retention. NoReread uses the SM-2 algorithm to schedule each card right before you'd forget it.
Why is rereading so popular if it's ineffective?
Because it's easy and creates an illusion of fluency: the text feels familiar, so you feel like you know it. That feeling disappears on exam day. Around 84% of students name rereading as a top strategy, and a majority believe cramming beats spacing — the research says the opposite.
Put the science to work.
Expert-built programs that are nothing but active recall and spaced repetition — the two things that actually move the needle.