Combine self and teacher assessment scores.
Blending a self-assessment with a marker's score is a weighted average, and the weight expresses how much the scheme trusts student judgement — commonly 20% to 30%. The more instructive output is the gap. A gap within a few points means you have internalised the rubric and can predict your own marks, which is the actual skill self-assessment is meant to build. A large positive gap points at criteria you are reading generously; a large negative one usually means you are discounting work that met the standard.
Combined self and teacher score
Combined = self score x self weight + teacher score x (1 - self weight)
Most schemes use 10% to 30%. Above that, the mark starts measuring confidence rather than performance, which is why the teacher weight is reported alongside the combined figure.
Because the gap is the learnable thing. Closing it means you can predict your marks before submitting, which lets you fix work while there is still time to fix it.
It costs you marks under any scheme that weights self-assessment, and it makes it harder to know when a piece of work is finished. Marking against the rubric wording rather than a feeling generally corrects it.