How to study for exams: what works, ranked by research
By the Braintoll team · · 7 min read
The short answer
The best way to study for an exam is to test yourself and to spread your studying over several days. A large review of study techniques rated exactly these two as highly effective, while rereading, highlighting and summarizing came out at the bottom. In practice: work through practice questions, past papers or flashcards instead of rereading your notes, review each topic several times with gaps of a few days, mix different problem types, and protect your sleep in the weeks before the exam, not just the night before.
On this page
Most students study the way that feels most productive: reading the notes again, highlighting the important parts, writing a neat summary. It feels like progress, because the material gets more familiar every time.
The research says that feeling is misleading. The methods that work best feel harder while you use them, and the most popular ones are among the least effective. This guide ranks the common study methods by the evidence behind them and shows how to use the best ones in the week before an exam.
Study methods ranked by evidence
In 2013, John Dunlosky and four colleagues reviewed hundreds of studies on ten popular learning techniques. They rated each one by how well it works across different students, subjects and kinds of tests:
| Method | What it means | Rating |
|---|---|---|
| Practice testing | Answering questions from memory: flashcards, practice questions, past papers | High |
| Spaced practice | Spreading study sessions over days and weeks instead of cramming | High |
| Interleaved practice | Mixing different topics or problem types in one session | Moderate |
| Elaborative interrogation | Asking yourself why a fact is true and answering it | Moderate |
| Self-explanation | Explaining how a new piece of information connects to what you know | Moderate |
| Summarizing | Writing summaries of what you read | Low |
| Highlighting | Marking important passages | Low |
| Keyword mnemonic | Linking a word to a memorable image (useful for vocabulary) | Low |
| Imagery for text | Picturing what you read | Low |
| Rereading | Reading the material again | Low |
“Low” doesn’t mean useless. Summaries can help if you’re good at writing them, and mnemonics work well for specific things like vocabulary. But they help less reliably and less broadly than the top two, which work for almost every subject, age and exam format.
Popular methods that weren’t in the review:
- Flashcards are practice testing, as long as you answer before you flip the card. Flipping and nodding is rereading in disguise. Choosing an app? See Anki vs Quizlet.
- The Feynman technique, explaining a topic in simple words as if to a beginner, is a form of self-explanation.
- Mind maps are fine for getting an overview of a topic. As a way to remember it, there’s little evidence that they beat testing yourself.
- Learning styles (visual, auditory and so on) have no good evidence behind them. A 2008 review by Harold Pashler and colleagues found no adequate basis for matching study methods to a learning style. Match the method to the material instead: diagrams for processes, practice problems for maths.
- The Pomodoro technique is a way to schedule breaks, not a study method. Use it if it keeps you going.
Why rereading feels good but doesn’t stick
A classic experiment by Henry Roediger and Jeffrey Karpicke shows the trap. Students learned a short text in four sessions. One group read it four times. Another read it once and then wrote down everything they could remember, three times.
Five minutes later, the rereaders did better, and they were more confident that they’d remember the text. A week later, it was the other way around: the rereaders recalled 40 percent, the group that had tested themselves 61 percent.
Rereading makes material feel familiar, and familiarity feels like knowing. But in the exam, nobody shows you the text. You have to pull the answer out of memory, and that’s exactly what testing yourself practises. More on how this works in our guide to active recall.
How to study for an exam: the methods in practice
Test yourself instead of rereading
Close the book and try to answer. Ways to do it:
- Past papers and practice questions, ideally under exam conditions.
- Flashcards with a question on the front, answered out loud or in writing before you flip.
- Blank page: write down everything you know about a topic, then check what’s missing.
- Questions from headings: turn each heading of your notes into a question and answer it without looking.
Getting answers wrong is part of it. A failed attempt followed by the correct answer still strengthens memory.
Spread your studying over days
Review each topic several times with gaps in between, instead of in one long session. The gaps let you forget a little, and retrieving something you’ve half forgotten makes it stick better. A simple pattern: learn a topic, review it the next day, again a few days later and once more shortly before the exam. Our guide to spaced repetition explains why, and the guide on how to make a study plan shows how to put the reviews into a calendar, with a free template.
Mix problem types
If your exam has calculations, don’t do twenty problems of one type and then twenty of the next. Shuffle them. Blocked practice feels smoother because you know which method to use before you read the problem. In the exam, you don’t. In a study by Doug Rohrer and Kelli Taylor, students who practised blocked did better during practice, but students who practised mixed did clearly better on the test a week later.
Ask why, and explain it to yourself
When you learn a fact, ask why it’s true. When you read a step in a solution, explain how it follows from the step before. Both make you connect new material with what you already know, and those connections are what you’ll use in an exam question you haven’t seen before.
A 7-day plan before an exam
If you have about a week, this order puts the high-rated methods first:
| Day | What to do |
|---|---|
| 7 | Do a past paper or practice test without preparing. It shows which topics are weak. |
| 6 | Work through the two or three weakest topics: learn, then test yourself. |
| 5 | Next weak topics. Review day 6’s topics briefly from memory. |
| 4 | Mixed practice questions across all topics. Turn every mistake into a flashcard. |
| 3 | Second practice test under exam conditions. |
| 2 | Go through your mistakes and flashcards. Review everything once from memory. |
| 1 | Short review of the flashcards only. Pack your things, stop in the early evening, sleep. |
With more than a week, start with the study plan instead and keep this week as the final one.
The night before the exam
Don’t try to learn new topics. Go through your flashcards or your list of mistakes once, then stop.
Sleep matters, but mostly the sleep you get in the weeks before. In a 2019 study at MIT, Kana Okano and colleagues tracked students’ sleep with fitness trackers through a chemistry course. Students who slept longer, better and more regularly in the week and month before a test got better grades; sleep in the single night before showed no clear link. So an all-nighter won’t rescue a semester, and a good night won’t save one either. What helps is regular sleep through the exam period.
Studying for several exams at once
Plan backwards from each exam date, and study two subjects a day instead of one subject a week, so the reviews for each subject keep coming. Start early with the exam that has the most material, not the one that comes first. The study plan guide has a section on this.
Keep the phone out of it
Every check of your phone during a study session breaks the concentration that testing yourself needs. Silence notifications, put the phone out of reach, and block the apps you open without thinking. Our guide to app blockers for studying compares the options.
Braintoll turns the phone itself into practice testing. You create flashcards from your exam material, or let the AI make them from your lecture slides, notes or a PDF (how that works). Then, when you open Instagram, TikTok or another app you’ve chosen, a few of those cards come first. The cards are scheduled with spaced repetition, so the two methods rated highest in the research happen in the moments you’d otherwise spend scrolling. Braintoll is free for one app, on Android and iPhone.
Common questions
What is the most effective way to study for an exam?
Testing yourself and spreading your study over several days. A large review of ten common techniques rated only these two as highly effective. Use practice questions, past papers or flashcards instead of rereading, and review each topic several times with gaps of a few days.
How many days before an exam should I start studying?
It depends on how much material there is, but at least a week for most exams, so you have time for two rounds of practice tests and reviews in between. For big university exams, start several weeks ahead and make a plan backwards from the exam date.
Is cramming bad?
Cramming can get you through a test the next day, but you forget most of it quickly, and you can’t review anything you got wrong. Spreading the same hours over several days gives you more on the day of the exam and far more afterwards, which matters when the next course builds on this one.
Is it better to study at night or in the morning?
There’s no time of day that works best for everyone. What matters more is that you study when you can concentrate, and that late sessions don’t cut into your sleep. Regular sleep in the weeks before an exam is linked to better grades.
Do learning styles matter for studying?
No. There is no good evidence that people learn better when the material matches a visual, auditory or other learning style. Choose the method by the material and the exam instead, and test yourself whatever the subject.