Sir – It was good to see the recent GCSE league tables given such prominent exposure (County schools now in top third, January 13) but they highlighted at least one anomaly of which readers should be aware. Both St Edward’s School and Radley College, in keeping with many other independent schools, offer the challenging International GCSE — the IGCSE — the results of which have yet to be reflected in Government league tables.

This skews results dramatically and gives a highly erroneous picture of the academic standing of individual schools.

Many newspapers print a narrative to this effect alongside the tables and The Oxford Times might consider adopting this approach in future. For instance, The Daily Telegraph qualifies the tables with the following sentence: Tables for independent schools can be misleading as they may not show the International GCSE, which is favoured in many schools.

A highly academic school will inevitably feature badly in these tables if they take high numbers of IGCSEs, particularly in English and Maths.

As schools like St Edward’s and Radley explore the new types of examinations on offer in order to stretch their pupils and keep intellectual curiosity alive, it is increasingly difficult to rely on crude statistics as a measure of a school’s suitability for an individual child.

Andrew Trotman, Warden, St Edward’s

Andrew Reekes, Acting Warden, Radley College