Alan Smithers: How can we clear up Blair's education legacy?

Tony Blair's valedictory education speech last week epitomises his 10 years in charge. Heart in the right place, but going off in all directions.

His two latest eye-catching announcements are the International Baccalaureate in every local education authority, and doubling the target for academies.

The IB is an excellent qualification for its original international purpose, but why promote it in England? Some schools have been attracted to it but, along with the Cambridge Pre-U and new university entrance tests, this has been a reaction to the inadequacies of A-levels. (A distorting university admissions tariff may also have had something to do with it.)

The obvious step is to sort out A-levels so that universities have access to a respected national scale where they can directly compare one applicant with another. Last week, the Government also outlined plans for doing just that through tougher questions and a new top grade.

This makes the IB announcement all the more puzzling. It is a general qualification testing all-round ability at a high level. It has to be passed in its entirety so that those who complete only parts will have little to show for two years' study. A-levels were introduced in the first place to overcome this all-or-nothing aspect of their predecessor, the higher school certificate, and also enable students to tailor their courses rather than having a version of breadth imposed upon them.

For schools to run the IB successfully they will, therefore, have to identify and recruit students of sufficient general ability to benefit.

Put into practice, Blair's plan seems to amount to pupils from across a local education authority converging on the one school and being academically selected - which is odd for a Labour government.

It can only be that Blair actually believes that diversity is a good thing. I had always assumed that this was a convenient fudge to enable the Labour Party to side-step the difficult issue of academic selection. But diversity for diversity's sake does make a kind of sense of the present secondary education policy. Rather than simplifying an already chaotic system, Blair's governments seem to have relished adding to the mix with, among others, specialist schools, trust schools, academies and others.

The reason given for the expansion of academies is that they have been so successful. Blair pointed to rising GCSE results and popularity with parents. But he does not appear to have made the obvious connection between the influx of new and different students, and rising results. One of the few consistent findings from research is that the main determinant of a school's exam performance is the intake. Pouring publicity and money into a school is good for it, but what of its neighbours?

Blair also boasts that four-fifths of secondary schools are now specialist. But specialisation means little. In a recent study of what makes a successful science school, we found that it was no more likely to specialise in science than, say, languages or arts. When challenged by the Education Select Committee, David Miliband, then the Schools Minister, said that it was best understood as a school improvement programme; in other words, a convenient fiction to prompt schools to stir themselves. Pity the parent who is now confronted with a confusing array of meaningless distinctions.

Blair's policies have undoubtedly been good for some individual schools, but whether for the system as a whole is more questionable. Diversity is supposed to pave the way for parental choice. But, inevitably, more parents will want their children to go to some schools than can be admitted.

Sorting out who gets the places is crucial. Academic selection is taboo, but there has to be selection of some kind, whether by proximity, faith or other means - which are arguably less fair. Parents with the know-how are able to manipulate, while the children the Government says it most wants to help end up in what is left.

Blair's die is cast. It will fall to his successors to provide the coherence that is lacking. In terms of qualifications, this means improving the system of examinations so that universities have a demonstrably fair way of distinguishing between applicants. Where the end is different - directly into employment, for example - it makes sense to have different qualifications, but not where the common goal is university.

For coherence at school level, it will be necessary to weave together all the disparate elements - quasi-specialist, academies, new faith schools, emerging trusts and the rest - so that all children have equivalent opportunities. Blair leaves a very fragmented system of secondary education and the urgent task of finding a new shape for it.

The writer is director of the Centre for Education and Employment Research, University of Buckingham

education@independent.co.uk