Students are voting with their feet for alternatives to A-levels and GCSE re-sits, with 163,000 signing on for General National Vocational Qualifications this year and numbers likely to exceed 250,000 next year.

Yet while the speed of take-up has outstripped all expectations and shows that GNVQs are meeting a real need, the row over how they match up to more traditional qualifications rumbles on.

All GNVQs have come in for some criticism, but the advanced level qualification in science has probably received more flak than most. This could be because fewer centres used to offer the BTEC (Business and Technology Education Council) national diploma, precursor of the advanced GNVQ in science, than in other subjects. Science teachers with little previous experience of non-traditonal teaching and assessment methods inevitably greeted the new qualification with suspicion.

But signs that teachers’ confidence in the qualification is growing are coming from centres which took part in last year’s GNVQ science pilot. Mike Coles, senior research fellow at the University of London Institute of Education, and one of the architects of the qualification, says: “In every case I have come across, teachers say they have got a much better cohort of students this year than they had last year. That seems to be much more of a function of their growing confidence than any real difference between the two student intakes. ”

With the first intake of advanced GNVQ science, with students not due to complete the course until next summer, it is too early to say whether university science departments view the qualification as a viable alternative to A-levels.

The picture may be clearer in a few weeks with the publication of a survey by the University of North London’s access unit into universities’ reactions to GNVQs.

At the moment teachers are reporting that their GNVQ students are getting more offers of places from the new universities than older institutions. This may reflect the prejudice against vocational studies that remains deeply embedded in the academic psyche - in this country at least. But it is also true that the GNVQ provides a better preparation for the vocational science-based degrees widely offered by the former polytechnics than for single science honours.

Andrew Hunt, director of the Nuffield Science in Practice project, which is supporting curriculum development work in GNVQ science, says that any student with a merit or distinction in the advanced qualification will have achieved a level of performance equal to that of A-level students. But he stresses that GNVQ students need to choose their higher education courses with care.

“If they went on a course that was very academic in its approach and which used assessment methods that were very much a continuation of the A-level system, then there is a danger they would find that difficult to cope with. ”

He also argues that while higher education now offers plenty of science-based courses for which the GNVQ is a good preparation, these courses are largely in applied areas of chemistry and biology.

“If someone wanted to study single science in physics, I think that would be a very doubtful choice because it’s quite clear that physicists are the least happy about the GNVQ specifications.”

The Institute of Physics has welcomed the arrival of an alternative to A-level that builds on the balanced approach of the GCSE double science award, but questions the nature and amount of physics in the advanced GNVQ science.

Catherine Wilson, the institute’s education manager for schools and colleges says: “We find it hard to believe that people could go into any serious study of physics-based science in higher education, whether it’s physics or engineering or even technical courses, without a better knowledge of electricity and electromagnetism than the GNVQ science gives them.”

The institute’s other main criticism, that GNVQ science is light on maths, is hotly disputed by some of those developing and delivering the qualification. They include Rick Nelms, curriculum co-ordinator for science, technology and maths at Long Road Sixth Form college in Cambridge and a member of the Science, Technology and Maths Council, the national body developing vocational qualifications in these areas.

He points out that in the core skills specifications, the GNVQ spells out exactly how much numeracy students need in a way that no other science qualification has ever done. Higher level maths is also an explicit component of some of the optional units, as well as being implicit in much of what students are asked to do in other units, he says.

Dr Nelms believes that the revised specifications which draw on lessons learnt from last year’s GNVQ science pilot have made it much easier for teachers to understand what underpinning knowledge their students need to meet the qualification’s performance criteria.

The new specifications also seem to have taken some of the heat out of other complaints about the qualification. Trevor Lund of Blackpool and the Fylde College, one of the centres in the pilot study, says: “The main criticism of the original specifications was that they were too overloaded with content and did not hang together to form a definite pattern from which to build a teaching scheme. With the extensive revision that has taken place, we now feel that the content is manageable.”

The content may be manageable, but it is no soft option, and the college has tightened up its entry requirements for GNVQ science, asking for the same GCSE passes as it does from students wanting to go on to A-level courses.

Another of the common criticisms from centres in the pilot study concerned the end of unit tests. Teachers complained about the technical quality and unpredictablility of the tests, and that questions did not always follow on from the units they were supposedly testing.

The test specifications, which all three GNVQ awarding bodies use, have now been revised and early signs are that last year’s deluge of complaints has shrunk to a trickle.

Ray Kirkwood, deputy director for development at the Royal Society of Arts, which ran the first series of tests using the new specifications last November, says: “We have for the first time received congratulatory notes from centres which were critical last year and which now say they were pleased to see that the level of the tests and the standards of the questions have settled down, and that the test specifications and the actual tests are producing a guide as to the standards to expect.”

But not all centres are equally congratulatory. Ian Smith, head of physics at Acklam Sixth-Form College in Middlesbrough, describes the pilot tests as “diabolical” and says the new ones are not much better. He is especially critical of the 70 per cent pass mark on tests which are supposed to measure the minimum standards acceptable, but which in fact seem designed to trip students up.

Arguing that some of the questions are just as likely to baffle A-level as GNVQ students, he says: “We have students who produce some excellent portfolio work, which we know is their own, and yet consistently fail the tests.”

It will be a pity if these problems are not sorted out. With over 7,000 students enrolled on advanced GNVQ science courses in the first year that they have been offered nationally, there is clearly a demand for an alternative to A-levels for those who are interested in a practical, problem-solving approach to science and who are likely to drop the subject at 16 without it.