How to Keep an Error Log That Actually Helps You Pass

Most candidates who keep an error log stop using it within a few weeks. Not because the idea is wrong, but because what they build usually isn't a log at all — it's a folder of pasted explanations that nobody rereads. A working error log looks different, and it is arguably the single most useful document a candidate creates during MRCPCH preparation.

What an error log is not

It is not a copy-paste of the question bank's explanation. Pasting text you didn't write does almost nothing for retention — you can highlight a paragraph and still have no memory of it a week later.

It is not a beautifully formatted set of notes, organised by topic with headers and colour-coding. Formatting takes time that should go toward writing and reviewing, and a log that takes an hour to maintain is a log that gets abandoned.

It is not something you plan to "tidy up later." Later never comes, and an untidied log is still more useful than a tidy one that was never written.

What an error log actually is

One sentence, in your own words, written the moment you get a question wrong — or right for the wrong reason.

Two examples show the difference between a useful entry and a wasted one:

"I missed that the child was four weeks old, not four months. The whole differential was different."

"I knew it was intussusception but selected the diagnosis instead of the next investigation. I didn't read the last line of the stem."

Neither of these is a summary of the explanation. Both are a precise account of where your own thinking went wrong. That precision is the entire value of the exercise — it turns a vague sense of "I got that wrong" into a specific, fixable habit.

Why writing it yourself is the part that works

Generating your own sentence forces you to identify the actual failure point, rather than accepting the explanation's version of events. A candidate who writes "I missed that the child was four weeks old" has done something a pasted explanation cannot do for them: they have located the exact moment their reasoning diverged from the correct path. That moment, once named, is far easier to catch next time.

Tag every entry with the type of error

A log without categories is just a diary. A log with categories becomes a diagnostic tool. Four tags cover most of what goes wrong:

Knowledge gap — you genuinely didn't know the fact or mechanism being tested.
Misread the stem — you had the knowledge, but missed a key word, age, or qualifier in the question.
Knew it but picked wrong — you recognised the correct answer as plausible but talked yourself out of it, or rushed the final choice.
Guessed and lost — you had no real basis for the answer you chose.

These categories matter more than they look like they should. After fifty entries, a pattern usually emerges, and the pattern is often not what you expected. A candidate who assumes their problem is knowledge often discovers, once entries are tagged, that the majority are "misread the stem" — which calls for slower, more deliberate reading, not more content revision. Tagging turns a hunch into a fact you can act on.

A practical example of the pattern showing up

Imagine forty entries tagged over a month. Twenty-five are "misread the stem," ten are "knowledge gap," and five are "guessed and lost." More question practice will not fix this candidate's score. Slower reading, and a habit of checking the final line of the stem before selecting an answer, will do more for their result than another two hundred questions.

Without tags, this same candidate might spend weeks re-reading textbooks for a knowledge gap that was never the real problem.

How to review it

Look at the log once a week, ideally at the same time — a weekend morning works well for most people. Read through the week's entries, count the tags, and ask what the dominant category is telling you. Adjust the coming week's revision based on the answer, not on a general sense of what "feels" weak.

A log reviewed weekly stays alive and keeps shaping your revision. A log written but never reviewed becomes a graveyard of forgotten mistakes — the writing still helps a little, but most of the value is in what the pattern reveals over time.

Common mistakes

Copying the question bank's explanation instead of writing your own sentence
Skipping entries when short on time, rather than writing the one-line version
Leaving entries untagged, which removes the ability to see the pattern
Building the log but never scheduling a weekly review
Treating a large log as an achievement in itself, rather than checking what it says

Three actions to take this week

Start a log today — a notebook, a plain document, anything you'll actually reopen. One sentence per error, no formatting required.
Add one of the four tags to every new entry, and go back and tag your last ten mistakes if you already have some.
Put a fixed weekly slot in your diary to read back through the week's entries and count the tags.

Closing thought

A log of fifty entries, written in your own words and reviewed every week, will tell you more about what to revise next than any textbook on the shelf. The habit is unglamorous, and that is exactly why most candidates skip it — and exactly why the ones who keep it tend to have a clearer idea of what's actually holding their score back.

A fuller version of this system, including a weekly review template, will feature in Paediatric Mentor's upcoming companion book for MRCPCH candidates.

Put this into practice: Try the free 3-Minute MRCPCH and start your own error log from the very first question.