As the Scottish Office published the fifth set of school exam results, Douglas Osler, senior chief inspector of schools, stressed that research was at an early stage. "If we ever did succeed in finding a measure which was both reliable and not unfair to schools it would in any case be an add-on to the existing tables not instead of them," Mr Osler said.
Mr Osler chairs a joint group on value-added approaches with the Convention of Scottish Local Authorities. Trials in 18 primary schools, centring on English and maths, found that it is possible to use 5-14 assessment in primary 4 and primary 7 to construct a value-added measure for primaries and perhaps the first two years of secondary school.
John Christie, director of education in Scottish Borders, who represents the authorities on the group, believes there is "some mileage in taking that study forward, perhaps by widening the sample". The group has proposed to Cosla that another 100 schools be included, possibly in the summer term. But Mr Osler warned: "You have to be certain of the pupil intake and have sophisticated ways of measuring it. You cannot just rely on postcodes."
The value-added approach could also founder on the hard realities of school and parent attitudes, according to Sally Brown of Stirling University. Professor Brown said: "It may be a much fairer way of making judgments about schools, but it is not helpful from the point of view of communication with parents. It is not about how schools are but how they would be performing if they all had similar intakes, which they do not.
"A school in a deprived area which was doing well on a value-added measure would probably find it of little value because people understand the raw scores. A more advantaged school which did well on raw scores but not value added would simply ignore the value added. And for a school doing well on both counts, it does not much matter."
The Inspectorate presented what Mr Osler called an "upbeat" judgement of the 1996 results, despite few overall advances. He stated: "It is not a system in despair needing major maintenance but one in a good state of repair maintaining itself. There will always be minor fluctuations every year which are not significant.
"In 1985, 10 per cent of leavers had five or more Highers which rose to 17 per cent in 1995. I cannot see that this is anything but progress. We are not looking for a quick fix but steady progress over time."
Archie McGlynn, head of the Inspectorate's audit unit, said it was important to acknowledge that standards had not slipped since "nothing can be taken for granted".
Mr Osler said the message was that "schools with similar catchments have very different kinds of results. It means that, together with high expectations of pupils, an emphasis on progression in learning and the reinforcement of a positive ethos, schools can and do make a difference.
"If you do not believe that, you paint a pretty depressing picture."