I am afraid that Bruce Macfarlane's explanation of the rise of the good degree in the 1980s (Letters, THES, July 3), that it could be due to students working harder, is just one of several extremely unlikely ones because the rise took place in different years in different subjects.
The only hypothesis that fits all the facts is that the rise is due to a change in the assessment method, most probably through the inclusion of course-work assessment, and that this took place at different times in different subjects.
Course-work assessment, as practised by most university examiners, tends to produce higher means and smaller standard deviations than assessment based on unseen examinations, but it cannot change the quality of student performance. To interpret the rise in marks that resulted from the use of course-work assessment as an improvement in grades is almost as absurd as to think that a temperature depends on whether it is measured with a mercury or an alcohol thermometer.
As for the maintenance of degree standards in the past three years, there is at least one other possible explanation: that course examination boards tend to give the same proportion of different degree classes from one year to another. There is evidence that this happens, and it would mask an absolute change of standards, which is in any case difficult to establish. We cannot be certain that standards remained the same, went up or went down in that period.
Professor of higher education, University College London