Controlled assessment, the controversial replacement for GCSE coursework, is "poor" and should be scrapped, the head of one of the big three exam boards has said.
The comments by Mark Dawe, OCR chief executive, are another major blow for the assessment method, heavily criticised since its introduction in 2009.
Exams regulator Ofqual has already said that it will conduct a subject-by- subject review of the case for controlled assessment - which allows pupils advance preparation for work they produce under controlled conditions. The watchdog's research last year found that some teachers had "deep-seated concerns" about the approach.
Now Mr Dawe has told TES: "We definitely need some form of assessment that stimulates learning. It would appear that controlled assessment is not achieving it and that it is a poor form of assessment. It doesn't differentiate between learners well enough. So we believe an alternative is needed."
Brian Lightman, general secretary of the Association of School and College Leaders, said: "Controlled assessment is very problematic - it is a low trust model that constrains teachers greatly in the time they can spend covering the specification.
"It certainly needs to be looked at. But we would not advocate piecemeal changes to GCSEs and think a much more fundamental look at the qualification needs to take place."
Controlled assessment was introduced because of concerns that the coursework it replaced had encouraged cheating. But it swiftly attracted criticisms of its own, with one teacher branding controlled assessment "insanity". The logistical difficulties of finding the time and space for pupils to work under controlled conditions for long periods of time have proved a major problem in some schools.
Another big exam board, AQA, even marketed an alternative to GCSEs for teachers concerned that controlled assessment was "taking away from their teaching time".
Last year, Ofqual reported concerns that the time taken up by controlled assessment was leading to "a narrowing of teaching" and fewer school trips. Four out of 10 secondary teachers said the assessment was difficult to implement, the watchdog found.
One head went further in December and told MPs on the Education Select Committee that controlled assessment was "ruining young people's lives".
Meanwhile, Bethan Marshall, senior lecturer in English education at King's College London, has argued that the abolition of coursework "fundamentally" changed English teaching and meant that pupils no longer learned essential drafting skills.
But Mr Dawe does not agree with her call for the restoration of coursework: he wants "something different". He believes that practical work is important in some subjects, such as field trips in geography, but said: "There are ways of encouraging that practical learning to happen without necessarily having to test the practical skills on the day."
He added that in some subjects there might be no need for controlled assessment, or a replacement.
His board also had "some concern" about the current A to G range of grades at GCSE, another aspect of the qualification that Ofqual is reviewing in time for changes in 2015.
"At the moment, GCSE covers level-one and level-two learning," Mr Dawe said. "Is this appropriate? Does it support the students and teachers in the best way? It is right to look at it."
Replacing GCSE coursework with controlled assessment was proposed as a way of raising public confidence in a qualification dogged by concerns that coursework encouraged plagiarism and cheating.
Some schools were criticised for supplying coursework essay plans and lists of key phrases to include, and giving pupils excessive assistance with redrafting. One teacher admitted that drafts would bounce back to pupils repeatedly until their work achieved the predicted grade.
But many teachers fiercely opposed abolishing coursework as it gave pupils who were uncomfortable with traditional exams the opportunity to do themselves justice.
Now, criticisms of controlled assessment may mean it faces the same fate as its predecessor.
THE GREAT DEBATE
TES is running the Great A-level Debate as part of exam watchdog Ofqual's consultation on the structure and design of the exams.
TES will be hosting online debates and surveys to find out what teachers think about the so-called "gold standard" and how they want the qualification to develop. The topics under discussion will include: Does grade inflation exist? Should all A levels have the same worth? Are A levels only useful as a university entrance exam?
Exam board OCR has agreed that it will use the views and findings generated by teachers in this discussion in its formal consultation response to Ofqual.
The best contributions will be in with a chance to be published in TES and win book tokens worth pound;50. This week's submissions are on page 7.
Original headline: Assessment judged to be `poor' by exam board