Spending more than two hours a night doing homework is linked to achieving better results in English, maths and science, according to a major study which has tracked the progress of 3,000 children over the past 15 years.
Spending any time doing homework showed benefits, but the effects were greater for students who put in two to three hours a night, according to the study published by the Department for Education.
The finding on homework runs counter to previous research which shows a "relatively modest" link between homework and achievement at secondary school.
The academics involved in the latest research say their study emphasises what students actually do, rather than how much work the school has set.
Pam Sammons, a professor of education at Oxford University, said that time spent on homework reflected the influence of the school – whether pupils were expected to do homework – as well as children's enjoyment of their subjects.
Sammons said: "That's one of the reasons Indian and Chinese children do better. They tend to put more time in. It's to do with your effort as well as your ability.
"What we're not saying is that everyone should do large amounts, but if we could shift some of those who spend no time or half an hour into [doing] one to two hours – one of the reasons private schools' results are better is that there's more expectation of homework."
The study controlled for social class, and whether pupils had a quiet place in which to do their homework, but still found a benefit, Sammons said.
The research was conducted by academics from the Institute of Education, Oxford and Birkbeck College, part of the university of London. It has tracked around 3,000 children from pre-school to the age of 14.
It also finds that students who reported that they enjoyed school got better results. "This is in contrast to findings during primary school where 'enjoyment of school' was not related to academic attainment," researchers said.
Schools could ensure children had a better experience by improving the "behavioural climate", making schoolwork interesting and making children feel supported by teachers, Sammons said.
The research shows that working-class parents can help their children succeed "against the odds" by having high aspirations for them.
Children who did well from disadvantaged backgrounds were backed by parents who valued learning and encouraged extra-curricular activities. "Parents' own resilience in the face of hardship provided a role model for their children's efforts," the research says.
The study underlines the importance of a good primary school. Children who attended an "academically effective" primary school did better at maths and science in later life. The study did not find a link with performance in English.
Ministers have scrapped guidelines setting out how much homework children should be set amid criticism that it can interfere with family life.
Under the last government, guidance was issued to all schools recommending they have a policy on homework.
The guidelines suggested children aged five to seven should be set an hour a week, rising to half an hour a night for seven- to 11-year-olds. Secondary schools were encouraged to set up to two and a half hours a night for children aged 14-16.
Scrapping the guidelines frees headteachers to set their own homework policy, the government says.
A new study from Stanford found that more than two hours of homework per night does not benefit high school students in advantaged communities.
The study looked at 4,317 students from 10 high schools in upper-middle class California communities. Fifty six percent of these students said homework was a primary source of stress.
Co-author Denise Pope is a senior lecturer at Stanford. She told USA TODAY that many teenagers spend too much time on homework each night, which results in excess stress and less time for developing critical life skills such as communicating with others and developing meaningful relationships.
Pope also says that this homework may be taking students longer than it should because of exhaustion and distractions from the Internet.
“Students have to think about whether they are getting enough sleep and doing their homework without distractions,” Pope says. “Is it really taking five hours or are they exhausted or over scheduled or are they on Facebook?”
The study found that students who spent more hours on homework tended to be more engaged in school, but were also more stressed about school work – they also had more health issues due to stress such as headaches, exhaustion, sleep deprivation, weight loss and stomach problems.
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Cam Curtin, 18, is a senior at Barnstable High School on Cape Cod, Mass. He has a 4.0 GPA and ranks in the top 10 in his class of 335 students. He says that he spends an average of three hours on homework each night.
“If I take into account all the time in between when I’m not staying on task it’s probably more like five hours a night,” Curtin says.
Curtin says that balancing athletics, friends and an academic schedule of six advanced placement classes leaves him exhausted most days. He also says that much of this homework is busywork.
“For example, my math class will have an assignment that says ‘problems one through 50’ and a lot of those questions are the same thing,” Curtin says. “So I’m doing the same thing over and over again when doing it three times would suffice.”
Pope says that busywork is not beneficial to a student’s education, yet high school students feel pressure to complete this work to benefit their grades.
“I’m exhausted a lot of the time especially when I get to the end of the five hours and then I have to choose to either sleep or to do the homework to get the good grade,” Curtin says. “I hold myself to a high standard of all A’s, so I try not to let my grades slip at all.”
Angie Cabral, 17, a junior at Deerfield Academy in Deerfield, Mass., says that Deerfield has a rule that homework for each class should take no more than 40 to 45 minutes a night. Students typically take five classes at a time so that would be 3.3 to 3.75 hours of homework per night.
“Homework adds a lot of stress, it is just another thing to juggle,” Cabral says. “But it’s a really big thing to juggle.” Cabral plays on Deerfield’s field hockey team and also does horse back riding all year long.
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Jillian Cahoon, a freshman at Fairfield University, 18, was a dedicated ballet dancer and the editor-in-chief of her school’s newspaper in high school. She says that hours of homework after rehearsals and newspaper production often left her exhausted and sick.
“There was a large amount of pressure to get good grades while doing extra curricular (activities) in order to get into the schools I wanted,” Cahoon says.
Despite these examples, the Association for Supervision and Curriculum Development (ASCD), a global community dedicated to excellence in learning, teaching and leading, compiled research for and against homework in 2007.
The organization found that “with only rare exceptions, the relationship between the amount of homework students do and their achievement outcomes was found to be positive and statistically significant.”
Still, Pope says that educators should move away from the notion that assigning a lot of homework will benefit students.
“Load and rigor do not equate,” Pope says. “You could have a challenging, meaningful curriculum that does not give an overload of homework.”
Joseph Soares, a sociology professor at Wake Forest, says that most studies show that high schools today give too much homework.
“Finland hardly has any (homework), maybe 20 minutes per night, and they out perform us,” Soares says.
Hilary Burns is a senior at Wake Forest University.
Hilary Burns, Wake Forest University, VOICES FROM CAMPUS