This study used educational survey data from 153,317 Grade 4 and 150,040 Grade 8 students in China to examine the relationship between homework time, academic achievement and learning anxiety.
By classifying time spent on homework into four variables, the study found that in-school homework time on weekdays had a positive effect on student achievement for both grades, with an even stronger effect on Grade 8 students. Out-of-school homework time on weekdays had a negative correlation with academic achievement and a positive correlation with learning anxiety, with a greater negative effect on Grade 8 than Grade 4.
The study recommends a maximum of 1 hour of homework for Grade 4 students and encourages Grade 8 students to have more out-of-school homework on weekends, with an average of more than 2.8 hours recommended. These findings can help teachers, practitioners and policy makers in planning homework assignments.