Mae gwybodaeth am ba mor dda y mae disgyblion 15 i 16 mlwydd oed wedi perfformio mewn arholiadau, a'u lefelau presenoldeb, yn cael eu defnyddio i fandio ysgolion. Wrth gyfrifo, rhoddir ystyriaeth hefyd i lefelau tlodi ymhlith disgyblion yr ysgol, gan fod hynny'n gallu cael effaith ar yr hyn y gall yr ysgol ei gyflawni.
Information about how well 15-16-year-olds have performed in examinations, and their level of attendance is used to band schools. The calculation also takes account of the level of poverty of pupils in the school as this can have an impact on what the school can achieve.