During the recent 14-19 consultation, it was argued by some people that the GCSE should be scrapped. But many others accepted that it serves several important functions, and that it is better to think in terms of evolution.

This means evolution on a large scale. GCSE maths alone has 700,000 entries, equal to the entire A-level entry. The entries for GCSE short courses and for General National Vocational Qualifications part 1 brought the total number of GCSE entries to more than 5.9 million in 2002.

The current range of GCSEs owes more to piecemeal developments than to a coherent and strategic approach. GCSEs come in a number of shapes and sizes: linear with coursework; modular with varying numbers of modules and exam sessions; short course, single and double award and with between one and three entry tiers. This does not appear to be a sound foundation for a possible English baccalaureate.

So how might GCSEs evolve ? The take-up of the new vocational GCSEs - engineering, for example - has been encouraging. Subject to final agreement, we expect to introduce new courses in construction and performing arts starting in September 2004. We have also proposed new “hybrid” GCSEs with a common core and optional vocational or general units.

There will be pilots of courses from September 2003 in areas related to science and geography.

The goal we are seeking is a coherent landscape of GCSE qualifications that can, in time, replace the current one. What might this look like? One possibility is as follows: the GCSE would become a “unitised” qualification. The basic building block would be the unit of learning - a discrete piece of knowledge, skills and understanding, with its own internal integrity. This is not a big step in the evolutionary chain.

A-levels, GNVQs and the National Vocational Qualifications are all unitised: the GCSE is now the only major qualification which is not.

There would be a compulsory combination of core units, which all would take as part of a general education, including English, maths, science and ICT.

All units would have a credit value reflecting the “volume” of learning involved. A certain number of credit points would be required for a full GCSE. There would be no “hybrid” units - it would be the qualification that might be “hybrid”, in that it could include units of different types. The core units might be called general units, the others specialist units. The latter would have roots in university-based curriculum when they would be assessed traditionally through written exams or they would derive their curriculum from industry and we would be looking for industry verification.

All would be called GCSE units and all would be of the same standard.

Much of this ground has already been broken. What then remains to be done? The current National Qualifications Framework describes three clear pathways at levels 1 to 3: foundation, intermediate and advanced level.

General is the clear academic stream; occupational is the NVQs levels 1 to 3. In the middle sit vocational qualifications - such as Btec, the progression awards and an increasing number of sector-specific qualifications. Currently, the pathway 14-year-olds step on to at foundation level is likely to be the one on which they will continue for the majority of their education and training. Certainly that is true for the academically gifted. Those for whom academic subjects are not appealing move across to the vocational pathway, largely by default.

The general qualifications pathway and the occupational pathway have their own clear purpose and integrity. It is the vocational pathway that is least purposeful, except for those young people who go on to the Higher National Certificates and Diplomas.

We need to replace pathways with stepping stones, to provide accumulating career and training opportunities that open up in front of young people rather than close off behind them. The purpose would be to allow young people to navigate their own way according to interest and aptitude, by selecting combinations of units which build the qualification in a way that suits them, and open up options for career development that can be pursued immediately or returned to later. The units would be structured so certain core units might serve as a basis for more than one “subject”; there would also be units which are pre-requisites for others, so that learning would be progressive and sequential. Students would be free to move across the full span rather than be confined to one of these pathways which are largely separate from each other.

Whatever the eventual landscape might look like, I think two things are certain. One is that the GCSE will become a progress check on the route towards advanced level study, training and employment, rather than an end point at age 16.

The second is that, inevitably, new and emerging strategies for 14-19 education will generate new approaches to teaching and learning and change operational relationships between schools, colleges and workplaces. In the process we will get a qualifications framework that better provides the nation with a template for development of the knowledge economy.

Dr Ken Boston is chief executive of the Qualifications and Curriculum Authority