A new approach to judging whether the grade standards of different exam boards are comparable has been researched by Ofqual.
The methods (Rasch modelling and Differential Step Functioning) have been used by the exams regulator to judge inter-board comparability in a subject, to make sure, so far as possible, that there is a level playing field for students.
The research on 16 subjects taken in 2015 finds that most of the cases of differences between boards were small – in most cases less than a fifth of a grade. In general, exam boards’ grade standards were more in line at the higher grades than the lower grades.
The findings were consistent with the statistical screening carried out by the boards in the autumn following each set of GCSE results.