THE Government's drive to raise standards with nightly homework for primary pupils may do more harm than good, according to new research.
Too much homework may damage primary pupils' results, a study of 20,000 11-year-olds found.
Education and Employment Secretary David Blunkett had recommended that 11-year-olds should do 50 minutes of homework every day, including 20 minutes of reading.
Eleven-year-olds who were set homework once a month achieved the highest scores in national tests in maths, science and reading, the study by Durham University academics found.
Children who did homework more frequently got lower test scores in all three subjects.
A "value added" analysis comparing children of similar ability and home background also showed that the schools which boosted test scores by the greatest amount were those which set the least homework.
The amount of homework set was found to be unrelated to pupils' ability. However, children from more educationally supportive homes tended to do more homework.
Pupils from nearly 500 schools were asked how often they did homework, as part of the Performance Indicators in Primary School project at Durham University.
Pupils reported doing most homework in reading - more than 40 per cent did reading homework more than once a week.
Significant time was devoted to maths, with one in five children doing maths homework more than once a week. Much less time was spent on science, with fewer than one in 10 children doing science homework more than once a week.
Dr Steve Farrow, director of primary initial teacher education at Durham University's school of education, said: "These were startling findings based on a huge number of children. There is an urgent need for further controlled trials in this area, before the current "more is better" school of educational policy-making commits primary school pupils to a homework regime.
"The evidence base for advice on the amount of homework that primary school pupils should do simply does not exist. This research highlights the gap in our knowledge."
The project backs the findings of academics from King's College, London, who observed that nine-year-olds who did maths homework once or twice a week did no better than those who only tackled homework occasionally.
It is also supported by research published last year by London's Institute of Education, which said homework could be a waste of time for primary pupils and can put children off learning. It also found that homework could cause tension at home and did not necessarily improve results or children's motivation.