* Using the criterion of five or more A*-C grades at GCSE, a standard reached by around 50 per cent of pupils is clearly invalid for comparing the results of the top 25 per cent of the ability range (“Tougher targets for table toppers”, TES, January 10).
The comparison based on the A*-B criterion revealed that, whereas 83 per cent of grammar-school pupils reached this target, 23 per cent of pupils from comprehensives and 11 per cent of secondary moderns did so.
Fred Naylor 2 Kingsdown House Kingsdown, Wiltshire