England's chief exam regulator has said that youngsters are being tested too much - and has questioned the value of having GCSEs at the end of compulsory education.

Ken Boston, the new chief executive of the Qualifications and Curriculum Authority (QCA), said his organisation had itself probably contributed to the "assessment frenzy".

He also said exam marking was "a cottage industry" run by "moonlighters" on piece work.

It should be done instead in day-long marking centres, in which subject specialists would mark different parts of candidates' scripts.

Proper balance

In an interview with BBC News, Dr Boston said the number of exams taken by England's teenagers was "at the upper end of the margin internationally".

Ken Boston: End the cottage industry

With that there was a culture in which assessment was "an end in itself".

"Optional tests are sold in large numbers. People - teachers - are encouraged to use them and I think probably believe they should be using them.

"We've got to stand back and say there needs to be a proper balance between the time given to teaching and the time given to assessing.

"And I think at the moment the indications are that we are not giving sufficient time to learning and to preparation at the expense of the examination process."

Tests to train for tests

Asked what should go then, he said he would be reviewing the optional tests with the QCA's board.

"I think that the QCA itself probably has fuelled the assessment frenzy by putting so much effort into the optional tests.

"They may well serve a very useful purpose, but if they're simply used as a training programme for further assessment then they're not fulfilling the fundamental purpose of assessment for learning, which is basically what assessment should be about."

He thought much of what was measured by GCSE exams at the age of 16 could be done by ongoing, internal assessment by teachers - especially as more and more people went on to do A-levels.

"I don't think it needs to be made a big, high-stakes, external operation," he said.

Huge demand

Dr Boston said that next summer's A-levels would involve the marking of some 17 million unit scripts - requiring 50,000 markers.

As there were only 250,000 teachers in England's secondary schools, not all experienced in teaching A-levels, a more efficient way of doing things was needed.

He suggested it might be time to have marking centres, as was done in some other countries.

"It is an excellent education system underpinned by an examination system which is really a cottage industry run by moonlighters and paid at piece rates and it simply cannot be sustained."

Day-long centres in which specialist markers dealt with parts of scripts would be much more efficient, he said.

Ongoing inquiry

An investigation into A-level marking was launched this autumn after schools complained that some pupils had achieved unexpectedly low grades.

Grades affecting about 100,000 people were re-examined. A total of 1,220 grades were found to be incorrect.

Next week, Mike Tomlinson will publish the second half of his findings from the A-level inquiry, which will look at the whole question of standards and how they can be maintained over time.

The chief executive of the Edexcel board, John Kerr - writing for BBC News Online - has also advocated simplifying and modernising the system, trusting teachers to do more marking within schools.