You have probably already read a list of revision techniques. Flashcards, mind maps, the Pomodoro timer, blurting, past papers, the Feynman technique, colour-coded notes. Every list gives them equal space, as if they were ten equally good options and you just pick the ones that suit your personality. In practice, some of them move your grade a lot, some barely move it, and one or two mostly make you feel productive while you forget the material at the same rate as before.
So this page does the thing the lists skip. It ranks them. Each technique gets a tier based on two things: what the research says about it, and whether it held up when I used it across Cambridge O Levels, AS and A Levels. Where I never tested a technique myself, I say so and give you the research verdict only. After the tier list you get a decision table (which technique for which subject, depending on how many weeks you have left) and a question log you can copy, which is the part that turns any of these techniques into a system.
On this page
The short answer
The revision techniques that work best all force you to produce the answer without looking: practice questions, past papers, blurting and self-testing. The ones that work worst let you look at the material and feel familiar with it: rereading, highlighting and copying out notes. Spacing your sessions out over weeks beats cramming the same hours into a few days.
The research on this is unusually clear. In 2013 a team of cognitive psychologists led by John Dunlosky reviewed ten popular study techniques and rated only two as high utility: practice testing and distributed (spaced) practice (the full paper is in Psychological Science in the Public Interest). Rereading, highlighting and summarising all came out as low utility. The Association for Psychological Science summary of that review is a two-minute read and worth it.
The part the research does not tell you is what to do after you test yourself. That is where most revision falls apart, and it is the part I can speak to from my own exams. A technique is only as good as what it forces you to produce without looking, and what you do with the gaps it exposes.
Revision techniques ranked: the tier list
S tier means build your revision around it. A tier means use it regularly. B tier means useful in specific situations. C tier means fine as a first pass, harmful as your main method.
| Tier | Technique | What the research says | My first-hand evidence |
|---|---|---|---|
| S | Timed past papers | Practice testing plus mixed topics: both high value | Core of my method. Last five years printed for every subject |
| S | Re-testing wrong and guessed questions a month later | Spaced practice plus testing | Core of my method. This is where marks were hiding |
| S | Blurting (free recall on a blank page) | A form of practice testing | What fixed my two memory-heavy subjects |
| A | Topical practice questions | Practice testing | Round one of my past-paper method |
| A | Flashcards with spaced review | Practice testing, if you answer before flipping | No first-hand test. Research verdict only |
| A | Self-explanation and the Feynman technique | Moderate utility | No first-hand test. Research verdict only |
| A | Interleaving (mixing topics in one session) | Moderate utility, strongest for maths and science problems | Built into timed papers, which mix topics by design |
| B | Asking “why” (elaborative interrogation) | Moderate utility | No first-hand test. Research verdict only |
| B | Mind maps | Not rated in the review. Useful only if drawn from memory | No first-hand test |
| C | Summarising notes | Low utility | No first-hand test. Research verdict only |
| C | Highlighting | Low utility | No first-hand test. Research verdict only |
| C | Rereading | Low utility | No first-hand test. Research verdict only |
Two things are missing from the table on purpose. The Pomodoro timer and schedules like the 2-3-5-7 method work as containers: they decide when you sit down, and say nothing about what you do once you are there. A 25-minute Pomodoro of rereading is still rereading. A 2-3-5-7 schedule is spacing, which is good, but only if each revisit is a test and not a reread.
Why the S tier is the S tier
Past papers sit at the top because they are three high-value techniques at once. You are testing yourself, the topics arrive mixed (so you have to recognise which method a question needs, which is half the exam), and the format, wording and timing match the real thing. I printed the last five years for every subject. By the end I was scoring 95 or more on science papers, and Physics and Chemistry were the straightforward part of my revision.
Blurting is in the S tier with a condition attached: it is the best tool I found for subjects that test memory, and a weaker one for subjects that test method. Islamiyat and Pakistan Studies were my two hardest subjects, because they reward memorisation and memory is not my strength. Writing everything I could remember on a blank page, then checking it, is what made them manageable. I wrote up the full method, with a blurt sheet you can copy, in my guide to the blurting method.
The month-later re-test is the one almost every list leaves out, and it earned its place the hard way. More on that in the 60/40 section below.
Why rereading is C tier even though everyone does it
Rereading feels like revision because recognition feels like memory. When you read a page for the third time, every line looks familiar, and your brain reports that as “I know this”. The exam does not ask you to recognise anything. It asks you to produce it from nothing, in your own words, under time pressure. Those are different skills, and only one of them is being practised when you reread.
Rereading is not useless. Reading a chapter once before you start testing yourself is fine. The problem is when it becomes the main event. If you finish a revision session and you never once had to write an answer without looking, that session was mostly a feeling.
Ali Abdaal’s walkthrough above covers the same evidence-based techniques and is a good companion if you prefer video.
Techniques the top pages push that I would skip or reframe
Choosing methods by learning style (visual, auditory, kinaesthetic) has no good research support, so pick by what the subject tests instead. Mnemonics and memory tricks were rated low utility in the Dunlosky review, and Cornell notes and dual coding (pairing words with diagrams, which The Learning Scientists explain here) are ways of making notes, so they only count as testing if you cover the answer and recall it before checking. Sleep, breaks and study groups matter, but like Pomodoro they are conditions around your revision, not the revision itself.
How to revise effectively: which technique for which subject
The single most useful decision you can make before planning anything is to sort your subjects by what they test. Some test memory (facts, dates, definitions, quotes). Some test method (can you apply a process to a question you have never seen). Most test a mix. Then factor in how long you have. The table uses Cambridge-style subjects, but it maps straight onto GCSE and A Level subjects with the same split.
| Subject type | 12+ weeks out | About 6 weeks out | About 2 weeks out |
|---|---|---|---|
| Memory-heavy (history, religious studies, biology definitions) | Blurt one topic per session, re-blurt on a spaced schedule | Blurt only topics that still have gaps. Start timed papers | Timed papers, then blurt whatever the papers exposed |
| Method-heavy (maths, physics, chemistry calculations) | Topical questions by chapter. Log every wrong or guessed one | Mixed timed papers, re-test your logged questions | Full timed papers only. Re-test your logged questions |
| Mixed (economics, computer science, psychology) | Topical questions plus blurting for definitions | Timed papers plus a blurt of each paper’s weak areas | Timed papers and your question log, nothing new |
If you only take one rule from the table: in the last two weeks, stop learning new material and stop making notes. Every hour goes into timed papers and into the questions you have already got wrong once. For the method-heavy side, my A Level Maths revision system walks through exactly how that looks with past papers, and the A Level Physics formula sheet separates what you get given in the exam from what you still have to memorise.
For free past papers and mark schemes, Physics & Maths Tutor and Save My Exams cover most Cambridge and UK boards, organised by topic and by year.
The 60/40 rule: what to do with the questions you get wrong
This is the part that matters more than which technique you pick.
Over a full revision period you might work through something like 1,000 practice questions in a single subject. Roughly 600 of them will be basic. You get them right, you understand why, and you never need to look at them again. The other 400 or so are the hard ones, the ones you got wrong, and the ones you got right by guessing. Those 400 are where almost all of your marks are won.
People ask about an 80/20 rule for revision. This is the version that held up for me, and the split is closer to 60/40 than 80/20. Most students spread their time evenly across all 1,000 questions, which means most of their time goes on questions they could already answer.
How I ran it
Round one was topical questions, chapter by chapter. I marked every question I got wrong, and also every one I was unsure about or guessed, even if the answer was right. A typical set might be 50 questions with 47 right, 3 wrong and 5 guessed. The useful number there is 8 questions to review, not a 94% score.
About a month later I went back to just those flagged questions. I expected to get every one right, because I remembered reviewing them. I got 60 to 70%. That gap is the whole reason this step exists. I repeated the flagged set one to three more times until it came back clean.
Round two was full yearly papers, three, five or up to ten years back depending on the subject, done under timed conditions with no mark scheme open. In round two I also flagged any question that felt difficult or confusing, even when I got it right, and those went into the same review pile.
The questions you guessed right are wrong answers that have not been caught yet.
A question log you can copy
Paste this into a spreadsheet or the back page of a notebook. One row per flagged question.
| Paper and question | Tag | Why I missed it | Re-test 1 | Re-test 2 | Clean? |
|---|---|---|---|---|---|
| 2022 Paper 1, Q7 | W (wrong) | Used the wrong formula | |||
| Chapter 4 topical, Q12 | G (guessed) | Could not explain why B was right | |||
| 2021 Paper 2, Q3 | H (hard, got it right) | Took far too long |
The tags are W for wrong, G for guessed right, and H for hard or confusing but right. Schedule the first re-test about a month after the original attempt, not the next day. A row only leaves the log when it comes back clean twice in a row. This works with any technique on the tier list: a blurt with gaps, a flashcard you hesitated on and a past-paper question all go in the same log.
The objections students actually raise
These come from students on r/GCSE and similar forums, where the same five complaints come up again and again.
“The smartest people in my year just say reread your notes.” Some of them probably do reread, and some of them are probably also doing a lot of practice they do not count as revision, like checking their homework answers or explaining topics to friends. Either way, one person’s habit is a weak signal next to a large research review. If rereading works for you, test it: reread a chapter, wait a week, then try to write it out from memory.
“Flashcards do not work for me. Exam questions work better.” That makes sense. Flashcards test isolated facts. Exam questions test whether you can use those facts in a context you did not choose. If questions work better for you, the research agrees with you, and you should make questions your main tool.
“I do active recall and flashcards but I still forget science processes.” A process (how a reaction works, the steps of a biological cycle) does not fit on a flashcard. Blurt the whole process on a blank page instead, start to finish, then check it. The gaps will show you exactly which step keeps falling out.
“How many hours a day should I revise, and when should I start?” Nobody can give you an honest universal number, and anyone who does is guessing. What I can tell you is that hours spent on the 400 hard questions are worth far more than hours spent on the 600 easy ones, so the number matters less than where it goes. Starting earlier mostly buys you room for spaced re-tests, which you cannot cram.
“Mind maps do not work for English Literature.” For a subject that tests argument and analysis, a mind map of themes is a summary, which is low utility. Writing timed paragraphs or essay plans from memory and comparing them to the mark scheme is the testing version of the same work.
The technique nobody ranks: the exam day itself
No revision list has a row for logistics, and it cost me more on one day than any technique choice did.
On one AS day I had a Physics practical in the morning and Psychology in the afternoon, at a different venue. I got to the Psychology exam about 15 minutes late, hungry and worn down. The knowledge was there. The energy and the time were not. That was a logistics failure, not a revision failure, and no technique would have fixed it.
So add one line to your plan: for every exam day, write down the venue, the travel time, what you will eat, and what happens between papers if you have two. My maths revision guide has an exam-day checklist you can borrow.
FAQ
What is the most effective revision technique?
Practice testing: answering questions without looking, ideally real past-paper questions under timed conditions. It was rated high utility in the 2013 Dunlosky review, and it was the backbone of my own revision. Pair it with spacing, meaning you return to the same material over weeks rather than in one block.
What is the 2-3-5-7 revision method?
It is a spacing schedule: you revisit a topic on a set ladder of days after first learning it, for example days 2, 3, 5 and 7. It works because it builds in spacing. It only works well if each revisit is a test, like a blurt or a set of questions, not a reread. I covered how to combine it with blurting in the blurting guide.
Is there an 80/20 rule for revision?
The version that held up for me is closer to 60/40. In my experience, of roughly 1,000 practice questions in a subject, about 600 are basic and need doing once. The other 400 (wrong, guessed or hard) are where your marks are, so they deserve most of your time.
Is 100 days enough to revise for GCSEs or A Levels?
For most students, yes, if the time is structured. 100 days is about 14 weeks, which puts you in the first column of the decision table: topical questions and blurting first, timed papers from around week 8, and only papers and your question log in the last two weeks.
Can you get 100% in an exam with these techniques?
In subjects with clear right answers, like the sciences and maths, scoring at or near full marks on papers is realistic once your question log is clean. I was targeting 100% in Physics and Chemistry and scoring 95 or more on papers. In essay subjects, full marks depend on examiner judgement, so aim for the top band rather than a perfect score.
What is the worst revision technique?
Rereading and highlighting as your main method. Both were rated low utility in the research, and both feel productive because familiar material feels learned.
Where this comes from
I sat Cambridge O Levels in 2014 (eight A*), AS Levels in 2015 (distinction across five subjects) and A Levels in 2016 (straight As across five subjects), every sitting in the May/June session. The past-paper method, the month-later re-test and the 60/40 split in this article are what I ran across every subject. The research verdicts come from the 2013 Dunlosky review and from The Learning Scientists, whose free guides on spaced practice and interleaving are worth reading. Where a row in the tier list says “research verdict only”, I did not test that technique myself. I do not have a teaching qualification and I am not a classroom teacher. I now tutor A Level Computer Science at Cambridge Computer Science Tutor. If you do one thing after reading this, start a question log today and put the next question you guess right in it.