Information about how well 15-16-year-olds have performed in examinations, and their level of attendance is used to band schools.
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.