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8 Study Techniques That Actually Work — and Why Rereading Your Notes Doesn't

A student writing from memory on a blank sheet of paper at a wooden desk, a book set aside

Most students study the way that feels most productive: reread the notes, highlight the textbook, go over the slides one more time. In 2013, five cognitive psychologists reviewed the evidence on ten popular study techniques — and rereading and highlighting came out near the bottom. The two that came out on top feel harder, which is exactly why so few students use them.

There are two separate questions in studying: when you do it, and what you actually do once you sit down. Focusity takes care of the first — it builds your study sessions into the free hours your class schedule actually leaves. This guide is about the second: eight techniques with real research behind them, and exactly how to use each one on your next midterm.

The short version

TechniqueWhat you actually doBest for
Active recallClose the book and write down what you rememberEverything — start here
Elaborative interrogationKeep asking “why is this true?”Concepts and mechanisms
Teach itExplain it out loud as if to a classmateFinding the gaps you didn't know about
Spaced repetitionCome back to it after a gap, not the same dayAnything you need in weeks, not tomorrow
InterleavingMix problem types instead of doing them in blocksMath, physics, stats, econ
Dual codingPair the words with a diagram you drawProcesses, systems, timelines
Protect your attentionNotifications off, phone out of reachEvery session
SleepNo all-nighters before the examKeeping what you studied

Why the way most students study doesn't stick

Two things work against you. The first is forgetting: in the 1880s the psychologist Hermann Ebbinghaus showed that most of what we learn fades within days unless we come back to it, and his “forgetting curve” has held up in modern replications. The second is sneakier. When you reread something, it feels familiar — and familiarity is easy to mistake for knowing it. The feeling is real; the memory underneath it is shallow.

That's why the habits that feel best are often the ones that work worst:

Feels productiveActually works
Rereading your notesClosing them and recalling what's in them
Highlighting the textbookTurning each section into a question
Cramming the night beforeShort reviews spread over days or weeks
Doing twenty problems of the same typeMixing problem types together
Recopying notes neatlyExplaining the material out loud

1. Active recall: close the book and pull it out of your head

Active recall means retrieving information from memory instead of looking at it again. It's the single most useful habit on this list, and the one the research is most confident about.

Why it works

Every time you pull something out of memory, you make it easier to pull out next time. In a classic experiment, students who read a passage and then tested themselves on it remembered less than rereaders after five minutes — but more after two days and after a week. The rereaders felt more confident; the testers remembered more. Roediger & Karpicke, 2006. The big 2013 review rated practice testing one of only two techniques with high utility. Dunlosky et al., 2013.

How to use it

2. Elaborative interrogation: keep asking “why?”

Elaborative interrogation is a formal name for a simple habit: for every fact, ask why is this true? or how does this connect to what I already know? — and answer it yourself before you look it up.

Why it works

A fact on its own is hard to hold on to. A fact attached to a reason is attached to everything that reason touches. The 2013 review rated this technique moderately useful — not as strong as testing, but a clear step up from rereading, and it pairs well with the first technique.

How to use it

3. Teach it: if you can't explain it simply, you don't know it yet

Two students in a library, one explaining a concept with his hands while the other listens

Often called the Feynman technique, after the physicist Richard Feynman: explain the idea in plain language, as if to a classmate who missed the lecture. Wherever you start waving your hands or reaching for the textbook's exact wording, you've found the part you don't understand.

Why it works

Even expecting to teach changes how you study. In one experiment, students told they would have to teach a passage to someone else recalled more of it, and organized it better, than students told they'd be tested — though in the end everyone was just tested. Nestojko et al., 2014.

How to use it

4. Spaced repetition: come back after a gap

A student on a city bus reviewing a stack of paper study cards by the window

Spaced repetition means reviewing the same material several times with gaps in between, instead of all at once. Three one-hour sessions spread across a week beat one three-hour session — even though the three-hour session feels like more work got done.

Why it works

A little forgetting between sessions is the point: pulling something back after you've partly lost it strengthens it more than reviewing it while it's fresh. The best gap depends on how far away the exam is. In a study of more than 1,350 people, the ideal gap was roughly 20 to 40 percent of the time until a test one week away, and a smaller share for tests months away. Cepeda et al., 2008.

How to use it

Focusity

Spacing only works if the second and third sessions actually happen. That's the part the app handles: it spreads review sessions for each course across the weeks before the exam, inside the free time your schedule really has — so “review in two days” lands on a day you're free.

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5. Interleaving: mix problem types instead of blocking them

Textbooks give you twenty problems on the same method in a row. Interleaving means mixing them: a derivative, then an integral, then a limit, then another derivative — so each problem forces you to first figure out which method it needs.

Why it works

Blocked practice lets you run on autopilot; the exam won't. In one experiment, students who practiced a set of geometry problems in blocks did better during practice — 89% versus 60% — but a week later, the interleaved group scored 63% against 20%. Rohrer & Taylor, 2007. It's the clearest example of why “it went well today” is a bad measure of learning.

How to use it

6. Dual coding: pair the words with a picture

Top-down view of a student's hands drawing a diagram of circles and arrows with colored pens

Dual coding means representing the same idea in two forms — words and a visual — so there are two routes back to it. It works best when you draw the visual: a flowchart of a process, a timeline, a diagram of how the parts of a system connect.

How to use it

7. Protect your attention: notifications off, phone out of reach

A student studying at a desk under a lamp, with a phone put away face down in an open drawer in the foreground

None of the techniques above work on half your attention, and the phone is the main thief.

Why it works

In one study, simply receiving a notification — without answering it — hurt performance on a task that needed focus about as much as actually using the phone did. Stothart et al., 2015. You may have heard a stronger claim, that a phone merely sitting on the desk drains your brainpower. That study went viral, but it failed to replicate in 2022, so we'd rest the advice on notifications, where the evidence is solid.

How to use it

8. Sleep: the study technique nobody counts

Sleep is when the brain consolidates what you learned during the day — and missing it damages what you learn next. In a 2007 study, people who skipped a single night of sleep were about 40% worse at forming new memories the following day. Yoo et al., 2007.

Tools that make these techniques easier

None of this needs an app — a pen and a blank page cover most of it. But a few tools take the bookkeeping off your hands:

ToolTechnique it supportsCost
AnkiSpaced repetition + active recallFree; iPhone app $24.99 once
QuizletActive recall and practice testsFree with limits
RemNoteNotes that turn into spaced flashcardsFree tier
BrainscapeFlashcards repeated by how confident you areFree tier

For the full research story in plain English, Make It Stick: The Science of Successful Learning (Brown, Roediger & McDaniel, 2014) is the book most study-skills advice is quietly built on. And if the problem isn't memory but nerves on exam day, see our guide to apps for test anxiety.

Putting it together: one study session, start to finish

  1. Phone away, notifications off.
  2. Warm up with recall: spend five minutes writing down what you remember from the last session on this course — that's spacing and active recall at once.
  3. New material in small pieces: read a section, close it, recall it, and ask “why?” about anything you got wrong.
  4. Practice mixed: if there are problems, shuffle this week's type in with older ones.
  5. Explain one thing out loud, or sketch it as a diagram.
  6. End with a list of what you couldn't recall. That list is where the next session starts.

Frequently asked questions

What is the most effective study technique?

Active recall — testing yourself instead of rereading — combined with spacing your reviews out over time. A major 2013 review of ten common techniques rated practice testing and distributed practice as the only two with high utility, and rated rereading and highlighting, the two most popular, as low.

How can I memorize things faster?

Stop measuring speed by how quickly the material starts to feel familiar. Read a section once, close it, and write down everything you remember; check, then do it again a day or two later. It feels slower and harder than rereading, but it is the version that is still there on exam day. Sleeping properly on the nights you study makes the rest of it stick.

Is rereading your notes a waste of time?

Not a complete waste, but close to the least efficient thing you can do with the time. Rereading makes material feel familiar, and familiarity is easily mistaken for knowing it. Read once to understand, then spend the rest of the time recalling it from memory and checking what you missed.

How long should I wait between study sessions on the same material?

It depends on how far away the exam is. In a large 2008 study, the best gap between two study sessions was roughly 20 to 40 percent of the time until the test for a test a week away, and a smaller share for tests months away. In practice: for a quiz next week, review after a day or two; for a final that is months away, a week or more between reviews works better than daily repetition.

Does sleep really affect memory?

Yes, in both directions. Sleep after studying helps consolidate what you learned, and missing it damages what you learn next: in a 2007 study, people who skipped one night of sleep were about 40 percent worse at forming new memories the following day. An all-nighter before an exam trades the material you already know for a few more hours of material you will not keep.

You know how to study. Now find the when.

Every technique here works better spread over time than squeezed into the last week — which means the sessions have to exist before the exam does.

Focusity turns your deadlines and exam dates into study sessions placed in the free time you actually have, spaced out the way this article recommends.

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