Recording children's progress every few weeks is a waste of teachers' time and could be damaging to pupils, a leaked government-commissioned report on assessment in schools has revealed.
The draft report from the Commission on Assessment Without Levels says many schools have introduced "vastly overburdensome systems to collect and record data" that take up a great deal of teachers' time.
"More frequent collection of assessment data may not only be a waste of time but could actually be damaging if actions are taken based on spurious or unreliable interpretations," the commissioners warn. "It could also encourage a rapid-but-superficial approach to learning."
The document adds that although many systems require tracking data to be entered every few weeks or even more frequently, changes in learning are unlikely to be reliably detected over a period of less than a year.
Against government policy
Kevin Courtney, deputy general secretary of the NUT, said the report was a "serious challenge to government policy on assessment". "No wonder the Department for Education is delaying its publication," he added.
And Dr Mary Bousted, general secretary of the ATL teaching union, said: "Obviously over-assessment can be damaging, but it's more than that. It is a complete distraction from the essential business of teaching and learning."
The report was leaked to newspaper The Guardian this week as education secretary Nicky Morgan told schools not to be "defeatist" about tackling workload.
In the draft report, the commissioners say they have repeatedly heard that schools' approaches to assessment are driven by expectations of what Ofsted wants to see. They stress that school leaders should not devise a system based on assumptions about inspectors, but with the sole aim of supporting pupils' achievement.
The report also says that the use of national curriculum levels had masked a "worrying lack of knowledge" in schools about the principles of assessment, which now needs to be addressed through training.
Russell Hobby, general secretary of the NAHT headteachers' union, would not comment on the leaked report but said excessive data collection was an issue. Much of the demand for this data came from the government and its agencies, he added.
"Left to their own devices, schools could create a system of assessment that was proportionate, useful and better than levels. But the trouble is, schools are not left to their own devices," Mr Hobby said.
"While a small amount of spreadsheets and colour coding can be valuable, schools are constantly asked for data. The pressure is not just from Ofsted but from academy trusts, the DfE, local authorities and their own governing bodies."
The Commission on Assessment Without Levels was set up to produce guidance for schools on how best to assess pupils after the system of national curriculum levels was scrapped.
Each level included a broad range of criteria that pupils were assessed against. But critics said this "best fit" model meant children could be graded at a certain level despite having serious gaps in their knowledge. Schools are now free to create or purchase their own assessment systems, which Ofsted will inspect.
The final report from the commission is expected in September. The DfE said it would not comment on leaked documents.