Active recall: the study habit that feels worse and works better
Rereading feels like learning. Trying to remember is uncomfortable, slower, and you get things wrong. It is also the thing that makes ideas stick. Try it yourself before you read about it.
Active recall means pulling information out of your memory instead of putting it in again: closing the book and explaining the chapter, answering a question before looking, writing what you remember on a blank page. It feels harder than rereading, and that effort is the point. In study after study, people who test themselves remember far more a week later than people who reread the same material for the same time.
Try it first: a two-minute experiment
Read the short passage below once, at your normal speed. Then hide it and write down everything you remember. Nothing you type leaves your browser.
How a swarm of bees picks a new home
In late spring, a crowded honeybee colony splits in two. The old queen leaves with about 10,000 workers, and the swarm settles on a tree branch while it decides where to live. A few hundred scout bees fly off to inspect possible homes: hollow trees, gaps in walls, empty hives. Back on the swarm, each scout performs a waggle dance for the site she found, and she dances longer for better sites. Other bees fly out to check those sites for themselves. A scout dances a little less each time she comes back, so support for weak sites fades away. The decision is made when about 15 scouts are at the same site at the same time. They start making a high-pitched piping sound, the swarm warms up its flight muscles, and the whole cloud of bees takes off for its new home.
Stuck? That's the useful part. Give it twenty more seconds before you check.
The passage had eight key points. Tick the ones you got, even in different words. We pre-ticked the ones we could spot in your answer; fix them if we got it wrong.
Compare with what you wrote
Whatever your score, notice how it felt. Hunting for the next point was slower and less pleasant than reading. Most people also find a few points they were sure they knew but can't bring back. That gap between "I read it" and "I can say it" is what active recall shows you, and closing it is what makes the memory stronger.
What active recall is (and isn't)
There are two ways to check whether you know something. You can recognize it: you see the answer and it looks familiar. Or you can recall it: you produce the answer yourself, with nothing in front of you. Recognition is easy and tells you very little. You can recognize a page of a book you could not explain to anyone.
Active recall is any study method that makes you do the second one. A few everyday examples:
| Instead of | Try |
|---|---|
| Rereading your highlights | Closing the book and listing the chapter's three main ideas |
| Reading a flashcard and flipping it | Saying the answer out loud before you flip |
| Summarizing with the book open | Summarizing from memory, then checking what you missed |
| Watching a lecture again | Explaining it to a friend, or to an empty room |
| Looking at a worked example | Solving the problem first, then comparing |
Researchers usually call this retrieval practice or the testing effect. "Testing" sounds like exams, but the tests here have no grades. They are just a way to make your brain go and fetch something.
Why it works: what the research says
The clearest demonstration is a 2006 study by Henry Roediger and Jeffrey Karpicke. Students read short science passages. Some read each passage four times. Others read it once and then spent the rest of the time writing down everything they could remember, much like the experiment above.
The rereaders did better.
Two things stand out. First, rereading wins in the short term, which is why it feels like it works: the material is fresh, and you would ace a quiz right away. Second, the rereaders also expected to remember more than the recall group did. They were confident and wrong. The psychologist Robert Bjork calls effortful methods like this desirable difficulties: the struggle that makes practice feel worse is the same thing that makes the memory last.
Other results point the same way:
- In a 2011 study in Science, Karpicke and Janell Blunt found that students who practised recalling a text remembered more of it a week later than students who built detailed concept maps of it, a technique that feels far more thorough.
- A 2013 review led by John Dunlosky rated ten popular study techniques. Practice testing was one of only two rated high utility. Highlighting and rereading were rated low.
Six ways to use active recall
You don't need flashcards or an app. Pick whichever fits what you are learning.
- The blank page. After a chapter, lecture or meeting, write everything you remember on an empty page for three minutes. Then open your source and fill the gaps in another colour. The gaps are your review list.
- Question-first notes. Write your notes as questions in the margin ("What are the two kinds of thinking?") with the answer hidden or on the next line. Later, read only the questions.
- Explain it out loud. Pretend a curious friend just asked you about the book. Where you start waving your hands is where you don't know it yet. This is the heart of the Feynman technique.
- Flashcards, used properly. Answer before you flip, every time. Keep cards small: one idea, one answer. Put the ones you miss back in the pile.
- Guess before you learn. Before a chapter, try to answer its title as a question. Being wrong first makes the right answer easier to remember when you read it.
- Teach or use it. Write a short post, explain a concept to a colleague, apply one idea this week. Using knowledge is recall with real stakes.
Make it stick: recall again, later
One round of recall helps. Several rounds, spread out, help much more. The ideal moment to recall something is when it has started to fade but you can still just about bring it back. Too soon and it is too easy; too late and it is gone.
A simple schedule that works for most people: recall the same material about a day later, then three days, a week, three weeks and a month after that. This is spaced repetition, and you can see what it does to the forgetting curve in our interactive chart, or get exact dates with the review schedule calculator.
You can test this with the bee passage above. Come back to this page tomorrow without rereading it, and it will offer to let you try again from memory. Most of what you lose, you lose in that first day.
Mistakes that quietly turn it back into rereading
- Peeking. Glancing at the answer "just to get started" turns recall into recognition. Give yourself at least ten honest seconds of trying first.
- Skipping the check. Always compare your answer with the source afterwards. Recall without feedback can strengthen a wrong version.
- Questions that are too easy. If you can answer it from the first word of the question, it isn't doing much. Ask for explanations, examples and connections, not just names.
- Doing it once. A single recall right after reading is good. The same recall three days later is where most of the long-term benefit comes from.
- Giving up when it feels bad. Struggling to remember is not a sign the method isn't working. It is the method working.
Where Prismo fits
I built Prismo to take care of the two parts of active recall that most people drop: writing good questions for everything they read, and remembering when to ask them. You write a few lines about what you learned, in your own words (which is already a round of recall). Prismo pulls out the ideas, writes questions from them in several formats, and brings each question back on a spaced schedule.
If you would rather do it by hand, everything on this page works with a notebook and a calendar. The habit matters much more than the tool.
Sources
- Roediger, H. L., & Karpicke, J. D. (2006). Test-enhanced learning: Taking memory tests improves long-term retention. Psychological Science, 17(3), 249–255.
- Karpicke, J. D., & Blunt, J. R. (2011). Retrieval practice produces more learning than elaborative studying with concept mapping. Science, 331(6018), 772–775.
- 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.
- Bjork, E. L., & Bjork, R. A. (2011). Making things hard on yourself, but in a good way: Creating desirable difficulties to enhance learning. In Psychology and the Real World, 56–64.
- Bee passage: Seeley, T. D. (2010). Honeybee Democracy. Princeton University Press; and Cornell Chronicle, 2006.
