Rereading your notes is inefficient, it wastes time and you're not maximising what you're actually learning about.
Plus, you're not learning the important skill of recalling, so here's the best way to learn that.
Why rereading can feel more effective than it is
Rereading isn't all bad, of course someone isn't going to immediately remember everything they learn on the first read, that's nearly impossible. But students mistake that with the only way to learn, and the most effective way to learn.
So let's try a thought experiment; imagine you're learning about photosynthesis, and you had no knowledge about it before. You read the same book again and again on photosynthesis, when all that time could be spent refining your knowledge, testing yourself, or learning about other things.
Now close your book, and answer:
Why does the plant need photosynthesis?
All of a sudden, it might not be so easy. You never received a question like this, and since your brain is unfamiliar with these questions, it's gonna work slower, and in a test or in an exam, you cannot be slow.
The problem is that recognising information and retrieving information are not the same thing.
Rereading gives you the answer while you study, which makes you more dependent on your notes rather than on your brain. In an exam, you normally don't have those notes, and even if you do, your brain won't know how to quickly recall the correct information, and translate that into an answer for the exam.
Studies have been done on retrieval practice, and it has constantly found that actively retrieving learned information can improve later retention whereas simply studying the material again doesn't have that same capability.
Turn your notes into something you have to solve
Instead of treating your notes as something to consume, treat them as something to work with.
For example, suppose your notes say:
The heart has four chambers. The right side sends deoxygenated blood to the lungs, while the left side sends oxygenated blood around the body.
You could reread that sentence several times.
Or you could close your notes and try to explain it yourself.
You could answer:
- How many chambers does the heart have?
- Where does the right side send blood?
- Which side pumps oxygenated blood around the body?
- What would be wrong with saying the right side pumps oxygenated blood to the body?
The information has not changed.
What changed is what your brain has to do with it.
Finding mistakes adds another layer
There is another way to make revision more active: examine information that contains a mistake and work out what is wrong.
For example:
The right side of the heart pumps oxygenated blood around the body.
Rather than simply being shown the correct fact, you now have to notice that something does not fit, identify the incorrect part, recall the correct information, and replace it.
That creates a different task from passive reading.
Research into learning from errors suggests that mistakes can sometimes become useful learning events when learners receive corrective feedback. Research on deliberately generating and correcting errors has also found benefits in some experiments, although results are not identical across every study or learning situation.
So the useful part is not simply seeing wrong information.
It is the process of:
- noticing the error,
- thinking about why it is wrong,
- finding the correct answer, and
- checking that correction against reliable material.
Try this instead of another reread
The next time you finish reading a section of your notes, do not immediately start reading it again.
Use this simple cycle:
1. Read
Read the section carefully enough to understand it.
Do not worry about memorising every sentence word for word.
2. Hide
Close the document, cover the page, or look away from your notes.
Remove the easy option of simply recognising the answer.
3. Retrieve
Ask yourself what you remember.
You could write a short summary, explain the idea aloud, answer a question, draw a diagram from memory, or list the main points.
4. Check
Open the original material again.
Compare your answer with it.
Look specifically for:
- facts you missed,
- facts you changed,
- ideas you misunderstood,
- details you were unsure about.
5. Correct
Do not just notice the difference and move on.
Actually correct your answer.
That correction is part of the revision.
Rereading vs active revision
| Rereading | Active revision |
|---|---|
| The information stays in front of you | You have to retrieve or evaluate information |
| It can quickly feel familiar | It exposes what you cannot yet remember |
| Easy to continue for long periods | Requires more mental effort |
| Useful for initial reading and checking | Useful for practising knowledge |
| Can hide gaps in understanding | Makes gaps easier to notice |
Active revision often feels harder.
That is not necessarily a bad sign.
If you cannot remember an answer, you have discovered something useful: you now know what needs more work.
Rereading the same page can make that weakness much less obvious.
You can also reverse the usual student-teacher relationship
Normally, a student answers a question and a teacher finds the mistakes.
You can reverse that.
Give yourself an answer that might be wrong and act like the teacher:
Where is the mistake?
Why is it wrong?
What should replace it?
What evidence supports the correction?
That is the idea behind Errata.
Errata turns study material you provide into revision exercises containing deliberate mistakes. Your job is to find those mistakes, correct them, and compare your corrections with feedback grounded in your source material.
Instead of only asking:
"Can I remember this?"
you also practise asking:
"Would I notice if this were wrong?"
Do not replace every study technique with one method
Finding mistakes is not the only useful way to study.
Neither is retrieval practice.
Neither is rereading.
Different tasks can require different approaches.
You might first read a chapter to understand it, retrieve the major ideas without looking, practise questions, correct your mistakes, and return to the original material when something does not make sense.
The goal is not to find one magical study technique.
The goal is to spend less time looking at information you already recognise and more time checking whether you can actually use it.
Make your next revision session active
When you next feel the urge to reread the same notes again, stop after the first read.
Hide them.
Try to reconstruct what you learned.
Check your answer.
Correct what went wrong.
And if you want to practise the same idea by finding deliberate mistakes instead, you can add your own study material to Errata and turn it into a revision exercise.
Your notes should not just be something you read.
Make them something you have to think about.