International Baccalaureate: 'My students walk the road less travelled'

So the Royal Society has joined the debate regarding A-levels and alternative courses of pre-university study, such as the International Baccalaureate Diploma ("No A-level physics at 16 per cent of schools", The Independent, 15 February 2011).

As Headmaster of a school that has, for the past five years, offered its sixth formers the choice between A-levels and the International Baccalaureate Diploma, I feel well placed to judge the differences and relative merits of the two programmes. We try to be even-handed in our advice. We recognise that neither route is "better": rather, we look to match the student to the programme – or vice-versa. To illustrate the point, our lower sixth has opted for the two programmes in roughly equal numbers.

Even though the IBD is hardly the new kid on the block, having been created in Geneva in 1968, it is still the road less travelled – so its structure, limitations and benefits require greater explanation to parents and prospective students than the better-known A-level route. That is changing of course but in the meantime I would argue that the great strengths of the IBD programme can be summarised in the concepts of breadth, independence, internationalism and stretch. Studying six subjects instead of four gives breadth. Many young people are not ready, at the age of 16, to specialise. The IBD, with its requirement of maths, a science, a humanities subject, a foreign language, one's own native language and one other elective subject, provides a highly respected but broad liberal arts education.

The IBD's independence over the past 40 years from the meddling of national governments of different hues has secured it from the buffeting of adversarial politics and also from the diminution of credibility that ensues from grade inflation. Not only does it provide an international academic passport that is widely accepted across the globe, but the culture of internationalism pervades the teaching of subjects to the benefit of its students.

Most strikingly of all, universities are increasingly, in our experience, drawn to IBD graduates because of two core elements: the extended essay and the theory of knowledge. It is here that the diploma most valuably stretches its students, preparing them for the challenges that lie ahead. The extended essay allows sixth formers the experience of writing an extended piece of work along the lines of what they will be required to do at university; the theory of knowledge, which focuses on critical thinking skills, enables students to arrive at university not only organised, focused and industrious but also equipped with the thinking skills required for success.

In an era in which one-in-four students in the UK fails to finish the course on which they embarked, and in which the escalating cost of higher education serves only to raise the stakes, the importance of this must not to be underestimated. My experience is that IBD graduates feel well-equipped when they arrive at university. It is not a question of coming up with the right answers but rather of being able to pose the right sort of questions. It's not enough simply to get young people to university: we need to ensure that they have the requisite skills to thrive when they are there.

Of course, the IBD isn't for everyone. For many, their happiest school day will come on the day they give up maths, or foreign languages, or English, or (in my case) chemistry. Many will therefore choose A-levels over the IBD in order to avoid certain subject areas – there is nothing ignoble or invalid about that. Others will wish to specialise as soon as possible: they know where they are headed and want to reach that destination as directly as possible. That is simply the way some people are hard-wired. Some destinations lend themselves to specialisation even at an early stage: for engineers and scientists, or those wishing to study veterinary science, the A-level route is recommended. In this sense, the choice between A-levels and IBD should be a personal one, a decision that should reflect how the student looks at the world.

Where we at Warminster School have found perhaps unanticipated benefits is in terms of curricular cross-fertilisation. The benefits of IBD have prompted us to consider how such features might be introduced to enrich the experience of our A-level students. The critical thinking element of the theory of knowledge has been reproduced by introducing Critical Thinking AS; almost all of our A-level students take this alongside four other AS-levels. We have also introduced the "Extended Project Qualification" at A-level, which allows students to create and independent piece of work (an artefact, an extended essay or a more practical project, for example) so that A-level students can also acquire the skills that will be needed at university. Many have successfully pursued this option – and the universities seem to be enthusiastic about it. While adding such elements to the A-level curriculum cannot entirely replicate the coherence or unity of the IBD, such an approach is of undoubted benefit to A-level students.

In that way, perhaps most unexpectedly of all, our A-level students have also benefited from the introduction of the IBD.

Martin Priestley has been Headmaster of Warminster School in Wiltshire since September 2006