That is the main short-term proposal of the report from the value-added working group set up by the School Curriculum and Assessment Authority (SCAA), to be published next Monday. It is understood that the group's proposals have been broadly approved by Gillian Shephard, the Education Secretary. She will issue a consultation document in the new year on the way the 1995 results should be presented.
For the longer term, the group recommends developing ways of measuring how well schools are doing given the performance of their pupils lower down the school system. But this could not be introduced into the GCSE league tables until 2000 at the earliest because of lack of nationwide information about prior attainment. It must wait until the pupils who take the first national tests at 11 next year sit their GCSEs.
The proposed school improvement index is based on the work of Michael Barber, professor of education at Keele University and a member of the group. For the 1995 results, it would involve giving a value of 100 to a school's 1992 GCSE results, and using that as a baseline for measuring subsequent improvement or deterioration.
Rather than the current method of ranking schools by the number of GCSE A to C grades achieved by pupils, the improvement index would allocate a score to each grade. It would thus be possible to measure the improvement in grades rather than just increases in the number of "passes".
Another central feature is that all fifth-year pupils would be included, not just those who had sat the exam, thus making it impossible for schools to massage the statistics by not entering candidates unlikely to succeed.
To iron out fluctuations between years, a three-year rolling average would be used (hence the figure for 1992 would be the average of 1991 plus 1992 plus 1993).
For the longer term, the report suggests setting up a trial of three "value-added" models in schools that could compare pupils' results with their achievements on entering the school.
These models would not take socio-economic factors into account and would be based solely on pupils' prior achievements. While the inclusion of social factors has not been ruled out for future work, SCAA is anxious to take one issue at a time. The working group is also thought to have been impressed by the difficulty of defining social background accurately enough to include it in a statistical analysis for use with school league tables.
The "value-added" index that could result from the trials might divide schools into three broad bands: those doing better than expected, roughly as expected, or worse than expected given their intake. Alternatively, an indicator could appear next to the raw results showing how far they were above or below what would be expected.
The working group is likely to point out that the attainment tests at 11 will need refining before they can be used for a value-added analysis. Simply placing pupils on the 10-level scale would be too crude a definition of their attainment at 11. The levels will need to be broken up.
Although a full "value-added" analysis of GCSE results will have to wait until at least 2000, it will be possible to trace the progress of pupils from 11 to 14, and from 14 to 16, earlier than that.