How to study effectively
Most study advice is generic, and some of it is actively wrong. Here are the techniques cognitive science says really work, the popular ones that waste your time, and a plan to put them together.
Find the score you need on your final exam to reach the grade you want.
Here is the uncomfortable truth about studying: the methods most students rely on are among the ones that work poorly. Rereading the textbook and running a highlighter down the page feel like studying, and they feel productive, but decades of research show they do very little for long-term memory. The good news is that the techniques that actually work are simple and free. This guide covers what the science supports, what to drop, and how to put it into a plan, so your hours of effort turn into marks instead of a false sense of security.
In short: the two most powerful study techniques are active recall (testing yourself instead of rereading) and spaced practice (short sessions spread over days, not one long cram). Add interleaving and explaining ideas in your own words, cut rereading and highlighting, protect your focus, and sleep. Then study toward a target: work out the grade you actually need and aim your effort there.
Why rereading and highlighting feel productive but barely work
When you reread a page you have seen before, it feels easy and familiar, and your brain reads that fluency as "I know this". That is the trap. Recognising information on the page is not the same as being able to recall it in an exam when the page is gone. This is called the fluency illusion, and it is why students who reread feel confident and then blank in the test. Highlighting has the same problem: it feels active, but it is mostly a decision about what to read again later, not an act of learning. A large review of learning techniques by Dunlosky and colleagues rated rereading, highlighting and simple summarising as among the least effective, despite being the most popular. The techniques below flip that.
The techniques ranked by evidence
Not all study methods are equal. Here is how they rate in the 2013 Dunlosky et al. review of ten common techniques, with the strongest at the top. These ratings come mostly from lab and classroom studies, so results vary by subject and student; the UNC Learning Center has practical tips too.
| Technique | Evidence | What it means |
|---|---|---|
| Active recall (self-testing) | Strong | Retrieve answers from memory instead of rereading |
| Spaced practice | Strong | Short sessions spread over days, not one long cram |
| Interleaving | Moderate | Mix related topics in one session rather than blocking one |
| Elaboration (Feynman-style) | Moderate | Explain ideas in your own words, as if teaching; closest to self-explanation in the review |
| Rereading notes | Low | Feels familiar, adds little; recognition is not recall |
| Highlighting | Low | Mostly marks what to reread; little learning on its own |
The takeaway is simple: spend most of your time on the top two, use the middle two to deepen understanding, and stop treating the bottom two as your main method.
Technique 1: Active recall, the single most powerful habit
Active recall means closing the book and forcing yourself to produce the answer from memory. The act of retrieval is what strengthens the memory, far more than seeing the answer again. This is the testing effect, one of the most reliable findings in learning research, summarised by the American Psychological Association: students who quiz themselves tend to remember more than those who restudy the same material for the same time.
How to do it: after reading a section, shut it and write down everything you remember, then check. Make flashcards with a question on one side and turn each heading in your notes into a question you answer out loud. Work past-paper questions before you feel ready, because getting it wrong and correcting it teaches more than rereading ever will. If a method feels hard and a little uncomfortable, that is usually a sign it is working.
Technique 2: Spaced practice, beating the forgetting curve
Your memory fades on a predictable curve: much of what you learn today fades within days unless you revisit it. Spaced practice works with that curve instead of against it. Five short sessions of 30 minutes across a week beat one three-hour cram, even though the total time is similar, because each time you return and struggle to recall, the memory is rebuilt stronger and lasts longer.
How to do it: start earlier and study each subject a little most days rather than in one block. A common rule of thumb, not a fixed law, is to review new material on day 1, then day 2, day 4, day 8 and day 15, each time from memory. It works for both kinds of material: recalling the steps of a maths method, or the key dates of a history topic. Cramming the night before can scrape a pass, but the knowledge fades fast, which is why crammers often remember little a week after the exam.
Interleaving and the Feynman technique
Interleaving means mixing related problems or topics in one session instead of doing twenty of the same type in a row. It feels harder and slower, and your practice performance looks worse, but it forces your brain to choose the right method each time, which is exactly what an exam demands. Studies find it especially helpful for maths-type problem solving.
The Feynman technique is elaboration in its simplest form: pick a concept and explain it, out loud or on paper, in plain language as if teaching a child. The moment you stumble or reach for jargon, you have found the gap in your understanding. Go back, fill it, and explain again. If you cannot explain it simply, you do not yet understand it.
Protect your focus, and sleep on it
Technique is wasted if your attention is shattered. A phone on the desk drains focus even face down, so put it in another room during study blocks. Many students use the Pomodoro method: 25 minutes of single-tasked work, then a 5 minute break, repeating with a longer break every few rounds. It keeps sessions short and intense, which research shows beats long, drifting ones.
Then respect sleep. Memories are consolidated overnight, so the all-nighter is self-defeating: you trade the very process that would have locked in what you studied. A good night's sleep before an exam does more than one more groggy hour of cramming.
A simple weekly study plan
Put it together and a week might look like this:
- Most days: one or two short, focused blocks per subject, phone away, using active recall (self-quizzing, past questions) rather than rereading.
- Spacing: revisit each topic within a day of first learning it, then again later in the week, then the next week.
- Mix it up: interleave related topics in a session instead of blocking one for hours.
- Weak spots: use the Feynman technique on anything you cannot explain simply, and spend more time there, not on what you already know.
- Before the exam: light review and a full night's sleep, not a panic cram.
Studying with ADHD or a tight deadline
If focus is hard, lean on structure rather than willpower: very short blocks, a written list of tiny next actions so starting is easy, studying alongside someone else (sometimes called body doubling), and removing the phone from the room entirely. The research base for these adaptations is thinner than for the core techniques above, and this is general study guidance, not medical advice, but they make the proven methods easier to begin and stick with.
With only a day or two before an exam, triage. Rank the topics by how many marks they carry and how weak you are on each, and spend your time on the high-mark topics you are weakest on first. Use active recall and past papers rather than rereading, do one fast recall pass over everything near the end, and still protect a night's sleep, because a rested brain recalls far more than an exhausted one.
Study toward the grade you actually need
Effort works best when it is aimed. Before a big exam, work out what score you need rather than studying blindly. For example, if your current grade is 78 percent and the final is worth 30 percent, the mark you need for an 80 percent target is (80 minus 78 times 0.7) divided by 0.3, which is about 85 percent. Aim for 85 overall instead and you would need about 101 percent on the final, which is impossible, so you would set a realistic goal. Our grade calculator does this instantly and gives the honest answer when a target is out of reach, so you can focus your limited hours where they move the needle. To see how a single result shifts your wider average, the GPA calculator does the same across your courses. Our guides on what grade you need on your final and how to calculate your GPA walk through the maths. Knowing the number turns vague worry into a clear plan.
Common study mistakes to avoid
These are the habits that waste the most time for the least return.
| Mistake | Do instead |
|---|---|
| Rereading and highlighting as your main method | Test yourself from memory (active recall) |
| One long cram the night before | Short sessions spread across days (spacing) |
| Studying what you already know because it feels good | Spend time on your weak spots |
| Phone on the desk | Phone in another room during blocks |
| Pulling an all-nighter | Sleep, so memories consolidate |
| Studying with no target | Work out the grade you need and aim for it |
Frequently asked questions
What is the most effective way to study, and the best way to study for exams?
Active recall, which means testing yourself from memory instead of rereading, combined with spaced practice, which means short sessions spread over several days. Together they were rated the two highest of the ten techniques reviewed in a major 2013 study.
Why does rereading not work well?
Rereading makes material feel familiar, and your brain mistakes that familiarity for knowledge. This is the fluency illusion. You can recognise the page but still fail to recall it in an exam, which is why self-testing works far better.
How long should I study for?
Shorter and more often beats long and rare. Focused blocks of 25 to 50 minutes with breaks, spread across most days, are more effective than occasional marathon sessions. Quality of attention matters more than hours logged.
Is cramming ever worth it?
Cramming can scrape a pass, but the knowledge disappears within days because it was never spaced or tested. For anything you need to keep, or cumulative exams, spaced practice over time wins easily.
How do I study for exams with a tight deadline?
Prioritise. Work out which topics carry the most marks and which you are weakest on, then self-test on those first. Use active recall and past questions rather than rereading, and protect sleep even when time is short.
Does studying harder improve my grade?
Studying smarter does. The same hours spent on active recall and spacing produce better results than more hours of rereading. Aiming at a specific target grade, using a grade calculator, helps you spend those hours where they count.
Sources: Dunlosky et al. (2013), Improving Students' Learning With Effective Learning Techniques, Psychological Science in the Public Interest; the UNC Learning Center; and the American Psychological Association. Written by the Calculator Den editorial team from published research, as general study guidance, not individual academic or medical advice.