Learning and memory
How to remember what you read
Short answer
Close the book and write down what you remember, then check it against the text. Students who tested themselves this way in a 2006 experiment recalled 56% of a passage a week later, against 42% for students who reread it. Review again after a gap of a few days, and treat rereading and highlighting as extras: a 2013 review of 10 study techniques rated both low utility.
A 2013 review of 10 study techniques gave its top rating to two: practice testing and spacing out study. Neither needs an app. With a book, practice testing means closing it and writing down what you remember, and spacing means doing that again days later. This guide fits both around a chapter or an article, with the numbers behind each step and the habits that rate lower than they feel.
Recall it before you reread it
In Henry Roediger and Jeffrey Karpicke’s 2006 experiments, college students read short prose passages, and then some took a recall test, writing down everything they could remember with no feedback, while others read the passage again. A week later the tested students recalled 56% of the passage and the rereaders 42%.
Rereading did win one comparison: when the test came five minutes after studying, the rereaders were ahead, 81% to 75%. In a second experiment, students who read a passage four times were the most confident they’d remember it, and a week later they recalled the least, 40%, against 61% for students who read it once and took three tests. Feeling sure after a reread was a poor guide to what stayed.
Rowland’s 2014 meta-analysis pooled 159 effect sizes and put the average advantage of testing over restudying at g = 0.50, a medium effect: the average tested person scored higher than about 69% of the restudy group. Studies that gave feedback on answers averaged g = 0.73. Most were lab studies, and the results varied a lot.
With a book, the test is simple to set. At the end of a chapter, close it and write down what you remember in any order: the main claims, names, numbers and examples. Then open the book and mark what you missed or got wrong. That check is the feedback.
Write one sentence from memory
If a full recall after every chapter is more than you’ll keep up, shrink it to one sentence. After each chapter or article, write from memory what it claimed and one detail that backs it up. For the section above, that might be: “Students who tested themselves on a passage recalled 56% a week later, against 42% for rereaders (Roediger and Karpicke, 2006).”
That sentence is free recall, the same kind of test Roediger and Karpicke’s students took, cut down so it’s quick enough to do every time. Keep the sentences in one note, each with its chapter or link. The list is what you review later, and when a sentence won’t come, you know which chapter to open again.
Scroll puts a question after every idea: one idea in about 40 to 100 words, then one quiz question with four options, which means picking an answer instead of writing one. Scroll lessons are short introductions for general interest. They aren’t medical, psychological or financial advice, and we haven’t tested whether reading them changes anyone’s memory or focus. For a decision about your health or money, talk to a qualified professional.
Come back after a few days
One recall straight after reading is the start. The forgetting curve is steepest in the first day, and testing’s advantage in Roediger and Karpicke’s data showed up a week later. The spacing studies are about the second look.
In Cepeda and colleagues’ 2008 study of more than 1,350 people, the best gap between two study sessions was about 20 to 40% of the time until the test when the test was a week away, falling to about 5 to 10% when it was a year away. For a book club meeting in a week, that puts a review of your sentences about 1.4 to 2.8 days after reading. For a book you want to be able to discuss a year from now, it’s about 18 to 37 days. The study used two sessions and trivia-style facts, so take the ratios as a starting point.
At each review, cover your sentences, look only at the chapter titles, and try to say each sentence before you uncover it. Then check. The spaced repetition schedule works out review dates from the date you need something by.
Make the answer yourself
The generation effect is the finding that people remember material better when they produce it than when they read it. Bertsch and colleagues’ 2007 review of 86 studies and 445 effect sizes put the average benefit at about 0.4 standard deviations, so the average person who generated the material beat about 65% of those who read it. Most of the studies used word lists in a lab.
With a book, that points to small changes in how you read. Before a chapter, look at its title and write down the question you think it answers, then read to find out whether you guessed right. Turn headings into questions. Explain a chapter out loud, or to someone else, without the book open. These are our applications of the idea to reading.
The Generation Effect
You remember information better when you generate it yourself rather than passively receive it. Completing the word "psych_l_gy" is more memorable than reading "psychology." Teaching a concept to someone else cements it more than re-reading notes. Active generation forces deeper processing.
Source Slamecka, N.J., & Graf, P. (1978). The generation effect.
Quick quiz
Which study method BEST exploits the generation effect?
What helps less than it feels like
In 2013 John Dunlosky and four colleagues rated 10 popular study techniques for how useful they were across learners, materials and tests. Only practice testing and spacing got the top rating. Rereading and highlighting, which students report relying on heavily, were rated low utility, along with summarization, the keyword mnemonic and imagery for text.
| Technique | What it means | Rating |
|---|---|---|
| Practice testing | Testing yourself on the material, or taking practice tests | High utility |
| Distributed practice | Spreading study sessions out over time | High utility |
| Elaborative interrogation | Explaining to yourself why a stated fact is true | Moderate utility |
| Self-explanation | Explaining how new information relates to what you know | Moderate utility |
| Interleaved practice | Mixing different kinds of problems or material in one session | Moderate utility |
| Summarization | Writing summaries of the text | Low utility |
| Highlighting or underlining | Marking passages that look important while reading | Low utility |
| Keyword mnemonic | Pairing a new word with a sound-alike word and a mental image | Low utility |
| Imagery for text | Forming mental pictures of the text while reading | Low utility |
| Rereading | Reading the text again after a first reading | Low utility |
Ratings from Dunlosky and colleagues (2013). They’re judgments the authors made from the evidence for each technique across learners and tasks, and the moderate ratings partly reflect limited evidence.
In the press release for the review, Dunlosky put the advice in one line: “By just replacing rereading with delayed retrieval practice, students would benefit.”
Low utility isn’t the same as useless. Rereading came out ahead when the test was five minutes later, and a highlight marks where to look when you check a recall. Both earn their place after you’ve tried to remember, as the check.
How long this adds to a book
Brysbaert’s 2019 meta-analysis of 190 studies and 18,573 participants put the average adult’s silent reading rate in English at 238 words per minute for nonfiction and 260 for fiction. Most adults fall between 175 and 300 words a minute for nonfiction, and the paper calls the often-quoted 300 an overestimate.
Say a nonfiction book runs 90,000 words over 20 chapters (both assumptions; your book will differ). Reading it at 238 words a minute takes about 378 minutes (6.3 hours). A two-minute sentence after each chapter adds 40 minutes, and two 10-minute reviews of your sentences add 20 more. That’s about an hour on top of 6.3 hours of reading, or about 16% more time, spent on the two techniques with the top rating in the 2013 review.
Before you close this page, write one sentence about what it said and check it against the first section. Then try it again from memory in a few days.
Drafted with AI assistance and checked against the sources listed on October 17, 2026.