Rereading and highlighting feel like studying, but the research on learning techniques rates them as low utility, while practice testing and spreading study over time are rated high. If you change one habit, replace some of your rereading with trying to recall the material from memory.
Key takeaways
- A large review of ten popular techniques found practice testing and distributed practice to have high utility, and highlighting and rereading to have low utility.
- Rereading creates familiarity. Familiarity feels like knowing, but it is not the same as being able to recall.
- Practice testing is answering from memory, which is what a flashcard review does.
- Distributed practice is spacing sessions out, which is what spaced repetition does.
- Highlighting is not useless as a first pass. It becomes useful when you go back and test yourself on it.
What the review found
In 2013, Dunlosky, Rawson, Marsh, Nathan and Willingham reviewed ten learning techniques in Psychological Science in the Public Interest (Improving students' learning with effective learning techniques). They rated each by how well the evidence showed it works across learning conditions, student characteristics, materials and tests.
| Rating | Techniques |
|---|---|
| High utility | Practice testing, distributed practice |
| Moderate utility | Elaborative interrogation, self-explanation, interleaved practice |
| Low utility | Summarization, highlighting, keyword mnemonic, imagery for text learning, rereading |
That does not mean the low-rated techniques never help. It means that, compared with the alternatives, they were less likely to give you durable learning for the time you spend. Rereading also leaves the forgetting curve, the steep early drop in memory that Ebbinghaus first measured, largely untouched.
Why rereading feels so good
Rereading is going back over the same text without testing yourself on it. For example, reading a chapter twice and calling it revised.
When you read a page a second time, it is easier to follow, and the ease is a signal your brain reads as "I know this". But recognising text in front of you is a different task from producing it with the page closed, and exams, conversations and real work ask for the second task.
Karpicke and Roediger's 2008 study in Science (The critical importance of retrieval for learning) shows the difference. Students learned foreign-language vocabulary under several conditions. Once a word had been recalled correctly, extra studying of it did not improve delayed recall, while extra testing improved it substantially. Students' own predictions of how well they would do did not match their results, which is why the feeling of knowing is a poor guide.
What to do instead
- After reading, close the book and write down what you remember. Then check the page.
- Turn highlights into questions. A highlight is a record, not a memory. See how to turn book highlights into cards and how to remember what you read.
- Space the tests out. Testing once is good; testing again after a growing gap is better. That is the idea behind spaced repetition, and the two together are covered in active recall vs spaced repetition.
- Keep cards small. How to write good flashcards shows how.
A quick test you can run yourself
For example, read one page of something you are studying. Close it. Write down everything you can recall in two minutes, then compare. The gap between what you expected to remember and what you wrote is the gap the research describes. This is a self-check, not a study result, but it shows the difference between recognising and recalling in a minute.
Where Cirello fits
A Cirello review is practice testing on a schedule: you see the prompt, answer from memory, reveal, and grade yourself. Cards can point at the book or page a highlight came from, so you review from the real source. When you grade, be honest, as explained in how to grade your flashcard reviews honestly. See the page on remembering book highlights, the flashcard app overview, or the broader guide to how to memorize anything.
Written by the Cirello team; see about Cirello and how we write for our editorial approach. Questions or corrections? Contact us at [email protected] or through the support page.
Sources
- 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. DOI
- Karpicke, J. D., & Roediger, H. L. (2008). The critical importance of retrieval for learning. Science, 319(5865), 966-968. PubMed