Self-marking fails quietly. Your score creeps up on paper while exam marks stay flat — because you trained yourself to be a lenient examiner.

1. Awarding method marks for intention

“I meant to integrate by parts” does not earn M1 without visible setup. The scheme marks what is written.

2. Ignoring follow-through rules

If line 2 is wrong, line 3 may be ft or zero. Do not cherry-pick the final number.

3. Essay band optimism

Band 3 language is specific. “Some good points” is Band 2 thinking. Read descriptors aloud — if you stumble, you are proving the band gap.

4. Marking while tired

Post-midnight generosity is real. Mark mornings, or mark one section at a time.

5. Skipping questions you “almost finished”

Incomplete attempts still teach timing. Mark what exists — note time management as the loss reason.

6. Never redoing

Marking without a five-minute redo is auditing without repair. The redo is where marks appear in the next paper.

7. Using non-Cambridge schemes

Third-party answer booklets help understanding but may not match exact Cambridge point splits. Always reconcile with the official PDF when possible.

Fixes that work

Two-colour pen: black attempt, red scheme ticks
Partner swap: mark each other’s papers once a week
Tool second pass: upload photos for mark-by-mark feedback after self-mark

Metric that matters

Track marks lost by category per week:

Method (M)
Accuracy (A)
Knowledge (B / KAA)
Evaluation (essays)
Time / incomplete

When one category dominates, your revision plan writes itself.

Closing

Past papers do not lie — self-marking sometimes does. Tighten the process and your mock scores become predictive, not comforting.