Judith Gillespie (July 31) faintly praises my praising of policy on school education in England before damning me for ignorance of the Nuffield Review of that country’s recent experience. Footnotes on sources are not the normal style of The TESS, and so Ms Gillespie may be forgiven for missing my rather cryptic allusion to the review’s findings on some of the locally harmful effects of competition, diversity and choice among schools. But these findings are no more than that: no research that I am aware of shows, for English schooling as a whole, that diversity has led to the destructive effects that its critics fear.

The review shows that diversity and competition may be harmful, not that they must be, and it also notes (p56) the evidence that specialist schools probably have directly improved attainment, although not by much.

Evidence across the system has to be statistical, not local and qualitative. And from what evidence we have, I reiterate that average attainment in England has risen and inequality has not risen (p49 of the Nuffield report, and in much more detail in the careful statistical analysis by Stephen Gorard and colleagues, dealing with both system-wide and local effects).

I cannot believe, as Ms Gillespie further seems to suggest, that the explanation of England’s progress might lie in different changes in the standards of external examinations in the different parts of the UK.

Given the close liaison among the examining bodies, and the need to maintain comparability of certificates, it is difficult to see how there could be so much divergence of standards as to explain such different trends in examination attainment as we have seen in the past decade. In any case, possibly different levels of rigour among examining bodies cannot explain England’s outperforming Wales, nor England’s outperforming Scotland in the international studies.

Lindsay Paterson, School of Education, University of Edinburgh.