Much as I approve of The TES editor’s comments on the stigmatising of schools and the lacklustre launch of the “coasting schools” initiative, I think Gerard Kelly has made a serious error in the final paragraph of his editorial in which he wrote about progress and social background (“Lost Ground: the policy label that does stick”, March 27).

It is just not the case that “80 per cent of the variation between pupils can be explained by differences in pupil background”.

When we had only simplistic background measures, such as free school meals, to set schools’ exam results in context, this seemed to be the case. But nowadays, with much greater access to information marking the intellectual progress that pupils make, this is no longer valid.

In fact, much more than 70 per cent in the variation between pupils’ outcomes at GCSE is dependent on differences in their initial attainments in earlier education.

The assertion of the link between social background and progress does a very real injustice to many of those schools, and in particular academies, which have set out to contest this in practice and have been remarkably successful.

Have a look, for example, at Sir John Cass School in Tower Hamlets in east London - one of many with high levels of social disadvantage yet attaining very high outcomes for its pupils.

Many schools have been very successful in “breaking the link” between disadvantage and educational success - and wasn’t this what, initially, the comprehensive school reform programme was supposed to be about? Isn’t there, perhaps, a need to celebrate those successes and help others to “learn the lessons”?

Professor David Jesson, York University.