At a session on the latest developments in the evolution of the STACS tables of exam results, Tony Flisch of the Glasgow-based Af Consultancy said that statistics were no more than "indicators". "We need to look for consistency in trends over time and over a range of statistics," Mr Flisch said.
He added: "There are often blips that cannot be explained and we must be careful not to demotivate teachers by rushing to tell them their results are really bad. We have got to look behind the figures over a period of time, and not waste time chasing statistical artefacts."
He suggested that schools analysing their results should take into account variations in the numbers being presented, at the number of no awards and at the performance of boys and girls as just some of the key factors in the overall picture.
Mr Flisch said that some students fare well in problem-solving, for example, but less so in their knowledge and understanding. But exam tables currently did not allow that analysis to be undertaken.
The revised STACS tables have caused some controversy because of the new "unified points scale" used to attach values to particular awards. Standard grade 1, for example, has 38 points with Standard grade 6 on eight points.
The conflict arises over Standard grade and Intermediate exams.
Intermediate 2 band 3 is placed on a par with Standard grade 1 and has the same number of points; Intermediate 2 band 6 is equated with Standard grade 2, while Intermediate 1 bands 3 and 6 have the same points as Standard grades 3 and 4.
Critics argue that the same equivalences cannot hold for all subjects.