Time and quality in and out of class: the roles of instruction and homework in mathematics achievement and interest

Which beliefs it touches

• C27 Homework and achievement sets a limit on it

  Grade 8, 2,808 pupils, 76 Chinese schools (cross-sectional, self-report): 30–60 min of daily maths homework went with slightly higher scores than ≤30 min (β = 0.06), longer times did not (β = 0.01); 60–90 min beat ≤30 min only when perceived homework quality was low (interaction β = −0.05); the homework-time block adds 0.3% of within-school variance and the time × quality terms another 0.3%. Homework quality, not time, went with maths interest (time not significant once quality is in the model, despite the abstract). Bounds what kind of homework the 7–12 link reflects. Full text read; corrected 2026-11-02.