A new testing regime, set to replace Sats in two years, will further narrow the curriculum, demotivate pupils and be less reliable than current tests, experts warned this week.
The most detailed criticism came from Chris Whetton, assistant director of the National Foundation for Educational Research, one of the developers of the new single-level tests. Another leading figure in the testing community described them as potentially a "disaster" - worse than this year's Sats marking fiasco, which led to the replacement of American contractor ETS Europe.
Pilots of single-level tests in English and maths have run in more than 400 schools since 2007. They are due to end next year.
When questioned this week about the Sats problems, Ed Balls, School's Secretary, hinted that single-level tests could replace Sats by 2010.
Under the pilots, all key stage 2 and 3 pupils are entered for a test set at a single national curriculum level up to twice a year whenever their teacher believes they are ready. The results are used for league tables, form the basis for cash bonuses for schools that do well, and are supposed to give pupils incentives to progress with their learning.
But in a speech to an international conference in Cambridge, Dr Whetton said the new tests:
- are based on the false assumption that "children's learning is an ordered progression and that movement is always forward";
- "raise the spectre" of narrower teaching to the test, since each new test can only cover a smaller part of the curriculum than Sats;
- could encourage pupils to rest on their laurels, since once a pupil gains a national curriculum level it cannot be taken away;
- are likely to produce less reliable results than Sats for technical reasons, and it might be too costly to develop new tests twice a year.
Finally, he said it might not be feasible to develop assessments designed to be taken by 14-year-olds and able 8-year-olds, as envisaged.
Dr Whetton, who is also president of the Association for Educational Assessment-Europe, said: "Proposed alternatives to national curriculum tests must be politically and educationally successful, and successful in assessment terms. These are hard to demonstrate for any system."
Professor Gordon Stobart, of the Institute of Education in London, said: "Hopes are being pinned on these tests as replacements for national curriculum assessments. But they aren't anything other than a pilot at this stage. The most serious worry is ... that they would lead to narrow teaching. This is not being addressed."
Tim Oates, group director of assessment research at testing body Cambridge Assessment, said: "We risk rushing into a disaster of much greater proportions than this summer with ETS."
The tests were criticised by other experts when the Government consulted on the pilot last year, although they have won plaudits from some teachers for reducing pupil stress.
A Department for Children, Schools and Families spokeswoman said: "We believe personalised testing will provide the consistency and reliability that end-of-key stage tests do. We have more faith in teachers than to think they will spend their time coaching pupils for these tests."
Allerton High School in Leeds is one of more than 180 new or refurbished schools set to open this term - the highest number for 30 years.
In all, 51 new academies are opening across England and Wales, taking the national total to 134. These are in addition to the new buildings.
The Government is firmly committed to opening at least 400 academies and regards the scaling up of the programme as imperative.
Teachers and children at Pudsey Grangefield School near Leeds said they were delighted with their new building in spite of snags that saw glazing and ICT systems still being installed during a visit by Rosie Winterton, the regional minister for Yorkshire and the Humber (above, with Allerton High pupils).
Among the features, IT firm RM has supplied Nintendo DS Lites and Sony PSPs for children to engage in brain-training games.
Ms Winterton, said: "These schools treat children as partners. They feel like communities, not institutions."