The candidates have sat the examination. The examiners have marked the scripts. Everyone has gone on holiday … except the chief examiners, for whom one more task remains. Before the Board’s computer can start to churn out the results slips, they must decide the formula for converting the marks into grades.

When there is just a single paper, and no course work, as with many AS examinations, this is straightforward enough. The chief examiner, making a judgement of the quality of the scripts against grade descriptions, backed up by past experience, will propose a set of grade boundaries – that is, the lowest marks which should achieve each of the available grades – and the conversion is then automatic. For example, if the grade boundaries are A 76, B 68, C 59, D 50, E 41 and N 32, then candidates with marks of 61, 99 and 30 will be graded C, A and U respectively.