The best way to learn something? Stop rereading it

It’s the night before the exam, the interview, the first day at the new job. You open your notes and read them again. Then again. By the third pass everything looks familiar, and familiar feels a lot like knowing.

It isn’t. Familiar is your brain recognising something it has seen before. Knowing is being able to bring it back when the page is closed. Decades of memory research point the same way: learning isn’t delivered into your head like a file you save. You build it, and most of the building happens when you try to get information out.

What is learning, really?

The everyday picture goes like this. You read or listen, the information goes in, and it’s stored. If that were true, the best way to learn would be to take in more, more often. Reread the chapter. Rewatch the lecture. Highlight the key bits in three colours.

Psychologists have been testing that picture for a long time, and it keeps coming up short. In 2013, John Dunlosky and four colleagues reviewed the evidence on ten popular study techniques. Rereading, highlighting and summarising, some of the things students rely on most, were rated “low utility”. Two techniques came out on top: practice testing, and spreading study out over time.

The retrieval practice experiment that flipped the script

In 2006, Henry Roediger and Jeffrey Karpicke at Washington University in St. Louis ran a neat experiment. Students had four short periods with a prose passage. One group read it four times. Another read it once, then spent the next three periods writing down everything they could remember, with no peeking and no feedback.

Tested five minutes later, the rereaders won: they recalled 83% of the passage, against 71% for the recall group. Tested a week later, the result flipped. The recall group still remembered 61%. The rereaders were down to 40%. Same material, same time, roughly half as much again remembered, just by spending the time differently.

The twist: the rereaders felt more confident they would remember. Rereading feels good because it’s smooth. Recalling feels worse because you keep hitting gaps. But those gaps are where the work happens. Each time you pull something out of memory, it becomes easier to find next time. Psychologists call this the testing effect, or retrieval practice, and it’s one of the best-supported findings in learning research.

A fair caveat: that study used university students and short texts in a lab. The wider body of evidence, including classroom studies covered in Dunlosky’s review, points the same way.

Does it help you understand, or just memorise?

Good question. Remembering facts isn’t the same as understanding them. In 2011, Karpicke and Janell Blunt tested exactly this in a study published in Science. Students learned from science texts either by building concept maps, detailed diagrams of how ideas connect, or by retrieval practice: reading, then recalling what they could from memory.

A week later, the retrieval group did better on straightforward questions and on inference questions, the kind that ask you to reason beyond what the text literally said. The advantage held even when the final test was to draw a concept map, the very thing the other group had practised. And again, students didn’t see it coming. Many expected concept mapping to work as well as retrieval, or better.

One study is never the last word. Other researchers questioned how well the concept-mapping group had been taught to map, and later work found the gap shrinks for people already experienced with concept maps. But the overall direction has held: recalling beats rearranging.

Why the struggle is the point: desirable difficulties

The UCLA psychologist Robert Bjork gave this pattern a name in 1994: desirable difficulties. Some conditions that make learning feel slower and harder in the moment, like testing yourself, spacing sessions out, or mixing topics together, produce learning that lasts longer.

The word doing the heavy lifting is “desirable”. Robert Bjork and Elizabeth Bjork have stressed that plenty of difficulties are just difficulties. A challenge helps when it makes you dig information out and connect it, and when you have enough background to meet it. Being dropped into a textbook three levels above you isn’t desirable. It’s just confusing.

So here’s the useful reframe. The strain of reaching for an answer you can almost get is often the feeling of learning working. Not every struggle is a good one. But smooth and easy is a poor sign that anything is sticking.

How to learn anything so it sticks: try this

1. Close the book, then write. After reading a chapter or watching a talk, put it away and write or say everything you remember. Then check what you missed.
2. Turn notes into questions. Instead of “interest rates affect inflation”, write “how do interest rates affect inflation, and why?” Answer it from memory later.
3. Space it out. Recall it again tomorrow, then in a few days, then next week. Short and spread out beats long and crammed.
4. Explain it to someone. Saying an idea out loud makes you retrieve it and put it in order. The bits you can’t explain are the bits you don’t know yet.
5. Let them ask you questions. A good question sends you back into your own memory and reasoning, which is exactly the effortful work the research rewards.
6. Distrust the warm glow. If a study session felt effortless, test yourself before you believe it worked.

Why talking ideas through works so well

Think about a real conversation on something that matters to you. Someone asks a question. You can’t look it up. You have to pull together what you think, put it into words, and notice where it wobbles. Then they ask a follow-up, and you do it again.

That’s retrieval, explanation and a manageable dose of difficulty, all at once. To be clear, the studies above tested students recalling texts, not friends talking, so this is applying the principle rather than a finding in itself. But it helps explain why explaining something to a friend can teach you more than another hour with a highlighter. Nobody can do your learning for you. A good conversation partner just gives you more reasons to do it yourself.

Putting it into practice on Everconnected

If you’d like to try this with someone new, Everconnected matches you with people who share your values and interests, for one-to-one conversations by voice. It’s free to join: create an account at app.everconnected.com, or get the app from the App Store or Google Play.

Questions people ask

Sources

1. Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249-255. doi.org/10.1111/j.1467-9280.2006.01693.x
2. Karpicke, J. D., & Blunt, J. R. (2011). Retrieval practice produces more learning than elaborative studying with concept mapping. Science, 331(6018), 772-775. doi.org/10.1126/science.1199327
3. Comment on “Retrieval practice produces more learning than elaborative studying with concept mapping” (2011). Science. doi.org/10.1126/science.1203698
4. 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. doi.org/10.1177/1529100612453266
5. Bjork, R. A. (1994). Memory and metamemory considerations in the training of human beings. In J. Metcalfe & A. Shimamura (Eds.), Metacognition: Knowing about knowing (pp. 185-205). MIT Press. bjorklab.psych.ucla.edu/robert-a-bjork-publications
6. Bjork, R. A., & Bjork, E. L. (2020). Desirable difficulties in theory and practice. Journal of Applied Research in Memory and Cognition, 9(4), 475-479. doi.org/10.1016/j.jarmac.2020.09.003