I write as a former admissions tutor and now director of the Sutton Trust, a charity which seeks to provide opportunities for non-privileged youngsters, particularly in terms of access to university.

Professor Caroline Gipps argued at the recent Headmasters and Headmistresses Conference in Dublin that the introduction in the UK of a US-style SAT for sixth-formers would make no difference to the number of working-class children entering higher education (TES, October 10). She quoted research that it was more a test of achievement than potential.

Research conducted by the National Foundation for Educational Research in 2001, which the Sutton Trust funded, suggested otherwise. This trial of 1,300 sixth-formers showed that the SAT measures a different construct from A-levels. Furthermore, 30 of the students from poorly-performing state schools, or 5 per cent of the cohort, scored highly enough on the SAT to be considered by a US Ivy League university. Only three of them achieved the A-level grades sufficient for consideration by a top UK university.

At the other end of the spectrum, in a research project at the University of Dundee the SAT has successfully identified students with capacity for higher education but whose Highers grades were lower than the minimum required for entry.

These findings are promising enough to warrant further investigation and we are discussing an operational trial of 50,000 secondary school students.

Dr Tessa Stone Director, The Sutton Trust Heritage House 21 Inner Park Road Wimbledon London SW19