An error log is just a running record of every question you got wrong on a practice test, plus why you got it wrong. That's the whole idea. The value isn't in the log itself — it's in what shows up once you've got twenty or thirty rows and can finally see which mistake keeps repeating.
Most students start one, fill in three rows after a practice test, and never open it again. The format below is built to survive that — it takes under a minute per mistake, which is the actual bar for whether you'll keep doing it.
What to track for each mistake
You only need six things, and you should be able to fill them in without thinking hard:
- Date and test — which practice test or problem set the question came from.
- Subject and category — not just "Math," but the specific skill, like "Algebra: linear equations in one variable." Vague categories produce vague patterns.
- Question number — so you can find it again if you want to redo it later.
- Error type — the single most important column. Why did you actually miss it? See the next section.
- One sentence on what happened — written immediately, while you still remember your thought process. "Forgot to check for extraneous solutions" is useful. "Made a mistake" is not.
- Reviewed? — a simple yes/no you update later, once you've actually gone back and restudied or redone the question.
Pick a short, fixed list of error types
The single biggest reason error logs fail is an error-type column that's different every time — "silly mistake," "wasn't paying attention," "brain fart," all meaning roughly the same thing but never grouping together when you go to count them. Pick a short list up front and reuse it every single time, even when it feels like a slightly awkward fit. A list of eight works well:
- Knowledge Gap
- Concept Misunderstanding
- Misapplied Concept
- Careless / Execution Error
- Misread the Question
- Wrong Strategy
- Time Management
- Guess / Other
If you're torn between two of these for a given mistake, that's worth reading about directly — see careless vs. conceptual errors.
Log mistakes right after you review the test, not weeks later
Log while you're reviewing your answers, not the next time you happen to open the spreadsheet. The "what happened" sentence is worthless if you write it two weeks later — by then you don't remember whether you rushed, misread the question, or genuinely didn't know the rule, and every entry defaults to a shrug.
Get the template
You can build this in a blank spreadsheet in five minutes, or start from a ready-made one: