Some parents have been caught out doing their children's homework and become "snippy" when their work received poor grades, a Wairarapa principal says.
Masterton Primary School principal Sue Walters said homework could be beneficial for children, but "learning should be done at school".
Results of the national CensusAtSchool survey found that Kiwi primary school students spent an average of 53 minutes doing homework every day.
Seventy-seven per cent of students aged 6-12 had done some homework on the night before the survey.
Mrs Walters said her school preferred students to take part in "invaluable" homework activities like cooking, rather than just hitting the books.
"You would definitely learn more working out how much breadcrumbs you need to crumb your six pieces of schnitzel than you would by having someone repeat 'Three fours are 12'."
Many homework tasks were specifically designed to engage parents, but it was important not to involve them too much.
Mrs Walters had encountered problems with parents doing their children's homework then becoming "snippy" when they didn't receive good marks.
But the other extreme was not healthy either, she said.
"There are some parents who see homework as a babysitting tool, and I've got a problem with that sort of homework."
While homework had its benefits, it was important not to cram too much in.
"The last school where I was principal was a decile 10 and by the time [the child] had done the ballet, attended a gymnastics class ... it was an overload to expect them to come home and learn their spelling words."
New Zealand-born Professor John Hattie, director of the Education Research Institute at Melbourne University, said the traditional homework model was not working for primary schools.
"For too many students, homework reinforces that they cannot learn by themselves, and cannot do the schoolwork.
"For these students, homework can undermine motivation, internalise incorrect routines and strategies, and reinforce less effective study habits, especially for elementary students."
The benefits of homework depended heavily on several factors. Students with high ability benefited more than those of lower ability, as did older rather than younger students, Professor Hattie said.
Homework achieved the best results in maths, and the least in science and social studies.
"It is a hotly-contested area, and my experience is that many parents judge the effectiveness of schools by the presence or amount of homework," he said.
The Ministry of Education does not have specific guidelines on how much homework teachers should assign, but encourages homework that engages both parent and child.
"Different schools have different homework policies - some set homework for older students but not younger ones, while others set homework for all students," a ministry spokesperson said.
"Evidence shows that homework activities that are designed to help parents to support children's learning at home and engage parents in what their child is doing at school, have the most positive results."
This isn't the first time the value of homework has been questioned.
US researchers from Virginia University looked at transcripts and data for more than 18,000 Year 10 students.
Their findings, published last year, showed homework assignments didn't translate into better grades.
And the 2006 US book, The Case Against Homework, suggested parents should insist teachers reduce the amount of homework assigned to pupils, design more valuable assignments, and avoid homework in holidays. APNZ