Teachers could receive more support in assessing pupils at 11 and 14 amid concerns that they are struggling to cope with the workload, TES Cymru has learnt.
Under new plans announced by the Assembly government this week, officials will explore how to help teachers assess pupils' progress in the absence of national tests.
Estyn, the Welsh inspectorate, will also investigate assessment arrangements and give its verdict on the system in a report due next year.
Teachers' unions and experts this week welcomed Estyn's investigation. Anna Brychan, director of the heads' union NAHT Cymru, said: "I think it (an independent evaluation) is merited, just to see if we are going down the right path."
Professor Richard Daugherty, whose landmark 2004 report led to the scrapping of national tests in Wales, also voiced his support.
The former head of education at Aberystwyth University told TES Cymru that he believed the assessment arrangements were in good shape, but that the system did need to be endorsed independently.
Instead of coaching pupils to sit national tests, teachers now judge their performance against a set of targets at the end of each key stage.
Samples of pupils' work are moderated within schools and within school clusters, while KS3 assessments are externally moderated by WJEC, the exam board.
Teacher assessment has received overwhelming support in Wales, although there have been gripes - especially from the NASUWT - over the workload it creates.
The union's Welsh arm has expressed concern that teachers are overburdened under the assessment system.
Meanwhile, the union is threatening strike action if Sats are abolished for 11-year-olds in England. It stands alone, however, with other teachers' unions threatening to go to the ballot box if their demands for Sats to be scrapped are not met.
Following a marking fiasco last summer, Sats for 14-year-olds have already been scrapped and replaced with teacher assessment in England.
Professor Daugherty said Sats had outlived their usefulness in the UK, but he did have some sympathy for Ed Balls, England's Schools Secretary, because public perception of testing is very different there.
"There's still a big attachment to tests in England and there are many political obstacles. It's not easy for Ed Balls to handle politically," he said.
"When I led the review in Wales, the climate was favourable (for abolishing Sats); the tests were having negative effects on schools. But the English public is very reliant on them."
But Professor Daugherty maintains that politicians in England were not listening to the experts - or looking to Wales for good practice.
A recent select committee report in England recommended trimming the national curriculum to give schools more freedom over what they teach, but it stopped short of suggesting scrapping Sats.
Professor Daugherty said: "The experts took a lot of evidence and made very strong recommendations, but the only bit of evidence in favour of Sats came from the Government. The Government is not listening; it's too far removed from what they (the experts) think."
Despite appreciating Mr Balls' difficult position, Professor Daugherty said politicians in England needed to think carefully about the country's testing regime and its effects on schools and pupils.
"It's not a matter of transferring Wales into England, but if Sats have outlived their usefulness in Wales then why would they want them in England?" he said.
An Assembly government spokesperson said of the external moderation of KS3 assessment in Wales: "During the development phase . care was taken to ensure close working with pilot schools and local authorities to ensure the new arrangements were both manageable and meaningful to schools."