Most candidates repeat the same six or seven mistakes for the whole preparation period, in different clothes. They get a percentage question wrong on Monday, a different percentage question wrong on Friday, and never notice that both failures came from dividing by the new value instead of the original.
An error log fixes this by forcing the question that a score alone cannot answer: why did this one go wrong? Once you have the cause, the repair is obvious, and the same cause stops costing you marks because you can now recognise it before you commit.
Every wrong answer in the HAT comes from one of three places. Naming the cause is the whole technique.
| Cause | What it looks like | How to fix it |
|---|---|---|
| Knowledge | You did not know the rule or formula. "I had no idea how to start." | Re-study the concept, then do five fresh questions of that type the same week |
| Procedure | You knew the rule but applied it in the wrong order, mis-drew a diagram, or missed a condition in the question | Write the correct procedure in one line and drill it on new examples until it is automatic |
| Attention | You knew it, could do it, and lost it anyway — misread "not", copied a number wrong, answered the wrong question | Adopt a fixed check (re-read the final line, check units and signs) and slow down on the last step |
The distribution is what matters. If most misses are knowledge, study more content. If they are procedure, drill. If they are attention, your problem is not the syllabus at all, and more studying will not touch it — you need habits, not facts.
Use a simple table, on paper or in a spreadsheet. Five columns are enough — resistance to adding more is what kills logs.
| Date | Question | What I did | Cause | Fix |
|---|---|---|---|---|
| Mar 04 | Percentage change from 300 to 350 | Divided 50 by 350 | Procedure | Percentage change always divides by the original. Write "change / original" at the top of rough paper |
| Mar 04 | Seating puzzle, question 3 | Answered from memory, no diagram | Procedure | Draw the row before reading the sub-questions; never more than 5 seconds of thinking without paper |
| Mar 06 | Sum of first n terms | Could not recall the formula | Knowledge | Learn n(n+1)/2 and test it on n=4 before trusting it |
| Mar 06 | Which option does not weaken the argument | Answered a "weakens" question | Attention | Underline the negative word in every question before answering |
Keep a separate single page for facts that keep costing you marks: percentage change divides by the original, "senior to" not "senior than", the 6-8-10 triangle, the contrapositive, the formula for work done. Target ten to fifteen entries. Copy it out in your own hand — the writing is part of the learning — and read it in the last week. This page is worth more in the final three days than any textbook.
Over three practice sets a candidate logs 21 errors. The causes split: 5 knowledge, 7 procedure, 9 attention. Their instinct is to buy another maths book.
The split says otherwise. Only 5 of 21 misses came from missing knowledge; 16 came from rule application and from slips. Adding content would target the smallest bucket. The correct plan is:
Two weeks later the same candidate logs 12 errors: 3 knowledge, 4 procedure, 5 attention. The reduced attention count proves the habit took hold — and no extra content was studied at all.
You knew the formula, set the problem up correctly, then divided by the new value instead of the original. Which cause is this?
Your log shows 9 attention errors and 5 knowledge errors this week. What is the best use of the next week?
Which practice most improves the log's accuracy?
Without looking back: name the three causes and one fix for each.
The answer: knowledge, fixed by re-studying the concept and doing five fresh questions; procedure, fixed by writing the rule in one line and drilling it; attention, fixed with a fixed check such as re-reading the question's final line.
The three causes of a wrong answer are knowledge, procedure and . A question I got right by still belongs in the log. Causes are written within hours, and every logged question is re-attempted cold after 3 to days.
Take your most recent set of wrong answers — from a mock, a drill, or this course's quizzes — and build the first four rows of your log. Five columns. Then count the causes and write the training they imply for the coming week.
Rows should be one line each: date, question, what I actually did, cause, fix. The "what I did" column is the important one — it is the difference between "got percentages wrong" and "divided by the new value", and only the second is repairable.
When you count, expect attention and procedure to dominate at first. This surprises candidates who assume they need more content, and it is why the log beats a score report: out of, say, ten misses, two might be knowledge, four procedure and four attention. Buying another book targets the two.
The weekly training then writes itself: for every knowledge miss, re-do the lesson and its quizzes; for every procedure miss, put a one-line rule on the forgetting page and do five fresh questions of that type; for every attention miss, name the specific habit (underline the instruction, re-read the final line, check units) and count surviving slips in the next set. Four or five consecutive weeks of this and the log starts shrinking on its own.
The log now tells you where marks are lost, and the mocks tell you whether the repairs worked. The coming lessons set the number you are aiming at, the routine for the day itself, and the energy plan that keeps both possible.