A student hands in an assignment on Tuesday. It comes back the following Wednesday with a mark and some red pen. By then they've covered two new topics, written something else, and stopped thinking about it entirely.
The feedback is accurate. It's also arriving to a person who no longer cares, about work they can't change, on a topic the class has moved past. That's not a teacher problem — it's how marking works when one person has ninety assignments. It just means the most useful information in the whole process shows up at the least useful moment.
Found before it's handed in, a mistake is a thing to fix. There's still time, the reasoning is fresh, and correcting it is the actual learning.
Found a week later, the same mistake is a mark. Nothing is fixed. The student reads the comment, feels bad for a second, and files it.
Same error, same feedback, completely different value. The only variable is timing.
Not a score. A score before submission is just an early version of the same problem.
What's useful is where it went wrong and why — this line, this step, the moles don't come out of the mass you used. Specific enough to act on, and stopping short of the correction, because being handed the fix teaches nothing and the student is right there with time to work it out.
There's a real difference between reading that you made an error and going back to find it yourself.
The second one requires re-entering the problem, locating the break, and repairing it — which is nearly the whole skill. It's also the version that survives to the next test, because the student did the finding.
That's why the note names the line and not the fix. The location is the help. The repair is theirs.
Mostly it changes the conversation. "Did you check it?" becomes a question with an answer instead of a nag, because there's something specific to check with.
And the assignment that gets handed in is closer to what the student can actually do — which makes the mark more honest, not less. A mark on work with the careless errors already removed is a better measure of understanding than one that's been dragged down by three arithmetic slips.
Assignment Check marks finished homework right or wrong with the reason — before it's handed in.
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