Keeping an Error Log

Why error logs fail

Plenty of people have tried keeping an error log and seen no benefit. Usually they spent all their time neatly copying out the problem and the model solution, and then never opened the notebook again. Copying feels like studying, but copying a solution while looking at it is completely different from working it out again yourself. The point of an error log is not the record; it is not making the same mistake again. That needs two steps: writing down why you went wrong, and redoing the problem later.

Sort the cause

When you look at a wrong answer, first classify why it happened. What you need to do depends entirely on whether you did not know the concept, knew it but could not apply it here, misread the question, slipped in a calculation, or ran out of time. A missing concept sends you back to the textbook; a misread question means changing how you read. Copy out only the solution without the cause, and that difference disappears.

• Missing concept: did not know the definition or formula
• Failed to apply: knew it but did not see how to use it here
• Misread: read the question wrongly
• Slip: the method was right but the working went wrong
• Time: could have solved it but ran out of time

What to record for each problem

You do not need many fields per problem. Rather than copying out the whole question, note the book, page and problem number, and paste in a cut-out or keep a photo if needed. The two lines that matter most are why you got it wrong and what you will do next time you see something similar. Write them as actions, such as "missed the sign condition" and "underline the conditions, then plug the answer back in to check", so that something actually changes next time.

• Source: book, page, problem number
• Cause: one of the categories above
• Key point: the concept or condition you missed
• Next action: what to do on a similar problem

Redoing is the real work

If you redo a problem on the same day you logged it, you remember the solution you just read and get it right easily. That is short-term memory, not skill. Only by redoing it from scratch a few days later, with the answer and solution covered, do you find out whether it is truly fixed. Write the redo date beside each entry and, on that day, gather those problems and work them. Mark the ones you get right; for the ones you miss again, write the cause again and set a new date. This is the part of the error log that actually raises marks.

Set a retirement rule

If you carry every mistake forever, the notebook quickly gets thick and redoing becomes a chore. So decide in advance when a problem leaves the list, for example after you solve it unaided twice in a row on separate days. Mark retired problems and take them off the redo list, and what remains is simply a list of where you are currently weak. Right before the exam, that remaining list is all you need to skim.

Look for patterns

Once a few dozen entries pile up, count the causes. If half are calculation slips, building a checking habit will show up in your marks faster than more concept study. If missing concepts cluster in one chapter, it is time to go back over that chapter from the start. If misreading is common, you need a habit of marking the conditions as you read. In this way an error log is both a record of individual problems and evidence of the weak spots in how you study.

Adapt it by subject

In subjects with worked solutions, such as maths and science, the important thing is noting at which step you went wrong. In multiple-choice style exams such as reading comprehension or social studies, it helps more to note why the option you chose was wrong and where in the passage or data the evidence for the right answer was. Things you simply did not know, like vocabulary or terms, are better handled in a separate word list or flashcards than in the error log. There is no need to force one format onto every subject.

Common mistakes

The most common mistake is focusing on making the notebook look nice. Time spent matching colours and tidying handwriting is better spent solving the problem one more time. Another missed opportunity is skipping problems you got right. If you guessed or were unsure while solving, it was effectively a wrong answer, so log it too. And finally, if you are not going to redo the problems, you will save time by not keeping the log at all.