The optimal amount of homework for 13-year-old students is about an hour a day, a study from Spain published last month in the Journal of Educational Psychology suggests. And spending too much time on homework, it found, is linked to a decrease in academic performance.
Researchers from the University of Oviedo surveyed 7,725 Spanish secondary school students on their homework habits. The students also took a test with 24 math and 24 science questions.
Students who did homework more frequently—i.e., every day—tended to do better on the test than those who did homework less frequently. And students who did their homework on their own performed better than those who had help. (The study controlled for factors such as gender and socioeconomic status.)
Although those who spent about 90 to 100 minutes a day on homework scored highest on the assessment, they didn’t outperform their peers who spent less time by very much. And students who did more than 90 to 100 minutes of homework posted lower scores.