Now Torry Academy in Aberdeen reports (page four) striking progress by pupils after mixed ability was abandoned and class sizes reduced. The results are highly encouraging but who is to say whether it is the nature of the abilit group in a class or its total size which is making the difference? Common sense might point to both. But again there has been little firm evidence in this country to chart a link between size of class and pupil achievement.
Other factors come into play: independent schools with small classes have good results, but they also choose their pupils. A gifted teacher can stimulate a class of 30 across the ability range. But not all teachers are "born". Most have to be made. Dealing with a smaller group whose abilities are much of a muchness should be more straightforward.
Henry Maitles, on the page opposite, is right to be puzzled by the lack of drive to reduce class sizes after primary 3. But his call to arms is not going to be welcome to those deep in post-McCrone budgeting, not least for the thousands of teachers needed for purposes other than reducing class sizes.