📒 How to Keep a Question Notebook (Error Log) That Really Works

A question notebook is a personal collection of the questions you could not solve or got wrong, written down with the right method and a short note about what tripped you up. It works because it makes you study your own weak spots instead of re-reading what you already know. The secret is not the notebook itself but the habit: record the question quickly, then come back to it until you can solve it alone.

Why a question notebook beats re-reading

Most students prepare for tests by reading their notes or the textbook again. It feels productive, but it mostly shows you things you already recognise. A wrong answer is different: it points at the exact idea, formula or step that is missing.

When you collect those questions in one place, you build a short, personal revision book. Before a Form Two Mathematics test or an end-of-term Biology exam, you do not need to read 200 pages. You need to go through the 30 questions that beat you last time.

There is also good evidence behind this. The testing effect (studied by Roediger & Karpicke, 2006, among others) shows that trying to recall an answer strengthens memory more than reading it again. Reviewing a question notebook is exactly that: you cover the solution and try again.

Paper or digital: which should you choose?

There is no single right answer. Choose the option you will actually keep using.

Paper notebook

• Good for writing out long working, diagrams and chemical equations by hand.
• No phone needed during study time.
• Hard to search, easy to lose, and it gets messy when you add questions from many subjects.

Digital notebook

• Always in your pocket, so you can add a question the moment you meet it.
• You can filter by subject, grade or source and find a question in seconds.
• A photo saves time: no copying out a long question or a graph.

Many students mix the two: they photograph the question and save it digitally, then solve it again on paper during review. In the Question Notebook in Let’s Study Book you can photograph a question from any book or test paper, crop it, add the options, your answer, the correct answer and a note, and later filter by subject, grade and source.

What to write for each question

A useful entry answers four questions. Keep it short; long entries are rarely re-read.

1. The question itself. A clear photo or a neat copy. Include any diagram or table.
2. Your answer. Write what you actually chose or wrote, even if it is embarrassing. It shows your thinking.
3. The correct answer and method. Not just “B”, but the key step: “use the area of a trapezium, not a rectangle”.
4. A one-line note on why you went wrong. For example: “forgot to convert cm to m”, “misread not”, “did not know the term osmosis”.

Tip: Write the note in your own words, as if you were warning a friend. “Watch the units!” will stick better than a copied textbook sentence.

It also helps to label the type of mistake: a knowledge gap, a careless slip, a misread question or running out of time. Each type needs a different fix. Our guide on learning from mistakes step by step explains these types in detail.

Which questions belong in the notebook

If you add everything, the notebook becomes a second textbook and you stop using it. Be selective:

• Add: questions you could not start, questions you got wrong for a reason you can name, and questions you got right only by guessing.
• Add: questions where you made the same careless slip for the second or third time.
• Skip: a one-off typo you spotted immediately and fully understand.
• Skip: questions on topics your teacher said are not in the syllabus.

A simple rule: if you would not be confident solving it again in a week, it goes in.

Give every question a status

A notebook only works if questions move out of it in your head. Give every entry a clear status so you know what to review next:

• Couldn’t solve – you still cannot do it without help. Ask a teacher or friend, or read the lesson again.
• Will review – you now understand the solution but have not yet solved it alone from scratch.
• Solved – you solved it again yourself, on a different day, without looking.

These are the same three statuses the Question Notebook in the app uses, so you can see at a glance what still needs work. Moving a question to “Solved” only after a clean, independent attempt is the most important habit in this whole guide.

A simple review routine

Collecting questions is the easy part. Reviewing them is where you gain marks. Try this weekly rhythm:

1. Same day or next day: look at the questions you added. Read the solution and make sure you understand each step. Status: Will review.
2. After a few days: cover the answer and try again on paper. If you succeed, keep it on Will review for one more check. If you fail, note what went wrong this time.
3. About a week later: try once more. If you solve it cleanly, mark it Solved.
4. Before a test: filter by the subject of the test and go through everything that is not yet Solved, then quickly re-test a few Solved ones.

Spacing your reviews out like this uses the spacing effect: memories last longer when you come back to them after a gap. You can read more in our guide to spaced repetition and the forgetting curve.

Tip: Ten minutes a day with your notebook is better than two hours once a month. Attach it to an existing habit, for example straight after dinner.

Common mistakes to avoid

• Copying the solution and never trying again. Reading the answer is not the same as being able to produce it.
• Making entries too long. If an entry takes ten minutes to write, you will stop writing them.
• Only recording hard questions. Repeated small slips cost many marks too.
• Keeping it secret from your teacher. Your notebook is the perfect thing to bring when you ask for help. In Let’s Study Book you can send a single notebook question to a friend or teacher and talk about it in a chat, while the rest of your notebook stays private.
• Never removing questions. Celebrate when a question becomes Solved. A shrinking “Couldn’t solve” list is real progress.

Getting started today

You do not need a perfect system. Start small:

1. Pick one subject where you lose the most marks.
2. After your next homework or class test, add three to five questions you got wrong.
3. Write your answer, the correct method and a one-line note for each.
4. Set a reminder to review them in two days.

After two or three weeks you will notice patterns: the same unit, the same kind of slip, the same word you keep misreading. That pattern is your personal study plan, and it is far more useful than any generic revision list.