A recent study of 7,451 teenagers in Spain examined the correlation between time spent on homework and academic achievement in maths and science. Results showed that homework done by the student independently for 60-70 minutes a day yielded the best results.
The students had a mean age of 13.78. They were given a questionnaire asking about frequency and duration of homework by subject, and whether they did homework independently or with parental help. Academic achievement was determined using maths and science standardised test scores adjusted for gender and socioeconomic status.
Results showed that students' maths and science scores increased when:
• Homework was assigned on a schedule.
• Students did their homework independently.
• Students were assigned 60-70 minutes of total homework. More than 90 minutes of homework a night had a detrimental effect on students' test scores.
The authors noted that students who did 70 minutes of homework with parental help scored lower than students who did 70 minutes of homework independently. They concluded that how the homework was done was more important than amount of time spent doing it, citing the possible explanation that self-regulated learning is related to higher academic achievement.
Source: Adolescents’ homework performance in mathematics and science: personal factors and teaching practices (2015), Journal of Educational Psychology