Sir, David Towers’ proposal of a norm-referenced system of grade allocation (letter, Aug 27) would be a return to the grading of the 1960s. The problem with fixed percentages covering middle grades is that grade bands become intolerably narrow, such that, in the centre of the bell-curve where most candidates perform, a score of 63 per cent in A-level chemistry in 1983 earned a B while 60 per cent resulted in a D.
What is needed is norm-referenced top grades to identify the really high flyers (A* say 5 per cent of candidates; A the next 10 per cent) with an E borderline set to define the bottom, say, 20 per cent; equal mark bands would determine the intermediate grades. Such a recalibrated system would maintain and even enhance standards; universities might like to reflect upon it too.
Dr John Guy
Principal of Farnborough Sixth Form College 1992-2010, Wheatley, Oxford