عبد العزيز اكرم أحمد رضوان2022-05-192022-05-191253https://drepo.sdl.edu.sa/handle/20.500.14154/10120The objectives of this study represent in the following: -To Identify the impact of different timing of feedback (immediate - delayed) in the e-learning on achievement and retention in mathematics for fourth primary class . - To Identify the impact of different levels of feedback (Media - corrective- explanatory) in e-learning on achievement and retention in mathematics for fourth primary class.ar-SAThesis