A revolution in examinations and testing which would dramatically increase teacher assessment and reduce external testing, was proposed this week by the Government’s chief exams adviser.

In a ground-breaking speech, Professor David Hargreaves said he believed that most teachers were incapable of making reliable judgments about pupils’ performance a decade ago.

But the national curriculum and testing had “transformed teachers’ understanding of what is to be taught and learned and their competence to assess what pupils achieve”.

The present testing regime was set up because politicians did not trust schools. Professor Hargreaves’ speech is the first sign that the climate may be about to change. In most European countries most assessment is already done by teachers, rather than external examiners.

Professor Hargreaves, chief executive of the Qualifications and Curriculum Authority, told his organisation’s annual conference that the present assessment system was “elaborate, extensive and expensive”. The sheer number of tests and examination papers that the system has to handle for pupils up to the age of 19 now exceeds 40 million annually.

“A relatively simple system has been added to in a piecemeal way and, perhaps, not surprisingly, has produced weaknesses that have made it a target of widespread criticism.”

He warned against “a limited and limiting debate over the quantity of assessment” and called for an emphasis on improving its quality.

Further far-reaching changes in testing could be achieved by harnessing new developments in information technology. “ICT now brings us to the beginning of a real revolution in assessment through a new partnership between education and the innovative private sector.”

At the same conference Education Secretary Estelle Morris outlined plans to end “the culture of leaving school at 16” and to introduce an American-style graduation certificate which would recognise achievement between the ages of 14 and 19.

She also announced more work-related courses and part-time schooling for some pupils and more choice for the brightest.

Professor Hargreaves said that abolishing the GCSE immediately would be “a grave mistake”. In a veiled criticism of the way the new AS-level was introduced he added: “We are surely learning that untested and untrialled innovations can so easily destabilise and confuse.”

But he and Ms Morris suggested that GCSE’s importance would be downgraded. He proposed changing GCSE into “intermediate” exams to fit into a new framework of qualifications, encompassing academic and vocational.

Students, parents and employers would have a much clearer idea of what a qualification meant if it fell into one of three levels, he said. The foundation level would be where most obtained a foothold in the qualification framework and could encompass GCSE grades D to G.

Intermediate level would include A to C grade GCSEs and level 2 national vocational qualifications. Advanced level would include AS-levels and A-levels and level 3 NVQs.

John Bangs, assistant secretary of the National Union of Teachers, said that Professor Hargreaves’ statement was the most radical he had heard on the current system. “The bells have started tolling for external testing. Assessment should inform teaching rather than be a bureaucratic bolt-on. It is also totally absurd to think you can extend the curriculum by simply adding exams. Quick fixes for a 14 to 19 education framework that will work are out.”

John Dunford, general secretary of the Secondary Heads Association, said:

“The examination system must be simplified and the reliance on external assessment reduced. Change is inevitable and the furore over AS-levels may prove to be the required catalyst.”

He added that the Government should create a new status for experienced teachers as chartered examiners approved by exam boards to mark tests and examinations.