Therefore, when aiming to evaluate whether pupil attainment in one dataset differs from that in another, it is important to control for the impact of ‘learning time’.
Felly, wrth geisio gwerthuso a yw cyrhaeddiad disgyblion mewn un set ddata yn wahanol i gyrhaeddiad disgyblion mewn un arall, mae'n bwysig rheoli effaith 'amser dysgu'.