The results suggest that spending time on homework is associated with higher academic achievement at secondary level

Caroline Sharp, researcher

The organisation collated evidence from various studies on homework carried out between 1988 and 2001, mainly in the USA and the UK.

The studies suggest there is a link between time spent on homework and achievement at secondary level, with children doing a reasonable amount of homework achieving better grades.

But children who underachieve include those who do a lot of homework as well as those who do very little.

The chief researcher, Caroline Sharp, said: "This major review shows that pupils and parents consider homework to be an important part of school life.

"The results suggest that spending time on homework is associated with higher academic achievement at secondary level.

"At primary level there is no conclusive evidence that homework boosts achievement."

Children who take part in homework clubs often perform well, researchers say

The research suggests that children who achieve most are those who have a positive attitude to homework and those who take part in after-school activities such as reading or homework clubs.

And parents who offer to help their children may not be always be doing them a favour.

The researchers said studies showed no clear relationship between the amount of parental help with homework and pupils' achievements at school.

The effect of parental involvement seems to vary with the parents' approach.

The researchers say parents can intervene in "more or less supportive ways".

Ms Sharp said: "Parents can help their children by encouraging them to get on with their homework and by getting involved in particular ways.

The studies point to parents helping by creating the right environment for homework: Giving a child a place to study and helping to limit distractions such as the television.

Primary schools

The research team says more studies should be carried out into the effects of homework, particularly at primary level.

The researchers say there is no conclusive evidence that homework boosts achievement at primary level.

The government recommends that children in years one and two (aged between four and six) have one hour of homework a week.

This is meant to rise to two-and-a-half hours a night for a child aged between 14 and 16.

The department for education suggests there are different purposes for homework.

It says the main aim for younger children should be to involve parents in a child's learning.

As children get older, the aim should be to encourage independent learning and to get pupils into the habit of studying, the department says.

A spokesperson for the Department of Education said: "We welcome this new research that shows the positive impact homework can have on achievement, particularly at secondary school level.

"We remain convinced that homework is important - our guidelines set broad recommendations on both the amount of time that pupils at different ages should be spending on homework and the type of homework that will be of most help."

Officials quoted a recent Mori poll which showed that 85% of those questioned thought it was important that 10 and 11-year-olds should do 30 minutes of homework of a day.

Ms Sharp believes the quality of homework is important: "Pupils want schools to set homework that clearly contributes to their learning and has adequate deadlines."