Teacher unions are divided over whether proposals to phase out national tests for 11 and 14-year-olds in favour of beefed-up teacher assessments will add to their members' workload.
The Daugherty review of statutory assessment in Wales says having both Sats and teacher assessments is wasteful, and that teaching to the tests has impoverished the curriculum.
But to ensure teacher assessments are seen as a credible substitute for test results, it recommends primary and secondary teachers should meet regularly to moderate each others' judgments of how pupils are doing at the end of key stages 2 and 3.
The review also proposes new skills tests in literacy, numeracy and problem-solving for 10-year-olds, to help inform their learning in the last year of primary and aid transition to secondary. These would be externally marked to avoid adding to workload.
The proposals have been broadly welcomed by heads, UCAC, the union for Welsh-speaking teachers, and the National Union of Teachers Cymru.
Dr Heledd Hayes, education officer for NUT Cymru, said: "The Daugherty review is a vote of confidence in teachers' professionalism." But NASUWT Cymru fears moderation of teacher assessments could create a whole new time-consuming bureaucracy, and expressed concerns about testing 10-year-olds.
Geraint Davies, its secretary, said: "We will still have formal testing in primary schools, and pupils being tested at only nine or 10. We have no problem with abolishing the Sats but are concerned they will be replaced by a workload-intensive assessment regime."
"The Daugherty review is in danger of creating a bureaucratic monster and something that would not serve any purpose for teachers and pupils."
The debate was fuelled by David Miliband, England's school standards minister, who claimed the Daugherty proposals did not mean the end of testing - just moving the age of pupils tested from 11 to 10.
A spokeswoman for the Welsh Assembly government said: "What Mr Miliband does in England is a matter for him and his department - our minister will decide what is best for Wales."
Anna Brychan, director of the National Association of Head Teachers Cymru, said: "Mr Miliband's comments do not seem to us to represent an accurate reading of Daugherty's findings, and would not benefit the pupils nor the parents who are trying to ensure that their children receive an education which maximises their abilities.
"We're happy with the thrust of Professor Daugherty's report. Class teachers are the people best placed to judge pupil development and achievement, but parents too are entitled to reassurance that decisions are fair and clear."
Welsh primary schools already use 20 other kinds of tests besides Sats to assess pupil learning, according to the Daugherty review. It believes Year 5 skills tests, designed to inform future learning, could make some of these other tests redundant and reduce the overall burden on young children.
Richard Daugherty, dean of arts at the University of Wales Aberystwyth, who chaired the assessment review group, said the needs of pupils were at the centre of its recommendations.
He said: "There's no doubt the moderation of teacher assessment involves more work for teachers. The compensating effect is the reduced workload associated with the administration and preparation of tests.
"Moderation is already going on. There are groups of teachers meeting to talk about the levels they are awarding pupils. It's not a statutory requirement but they think it's important."
John Hopkins, president of the Secondary Heads' Association Cymru, agreed that the proposals, if well-managed, should be workload neutral. For example, teachers released from "pointless" exam invigilation would have more time in the summer to liaise with primary colleagues over Y6 assessments.
"We would be replacing a non-teaching task with a professional one. And if there is a slight increase in workload, it will be balanced by the benefit."
Jane Davidson, education and lifelong learning minister, has welcomed the Daugherty report and a parallel but unpublished review of the curriculum undertaken by ACCAC, the qualifications, curriculum and assessment authority for Wales. She is expected to give the government's response to both documents later this summer.