Value-added approaches to measuring a school's effectiveness should provide "a broad indicator for school self-evaluation not a conclusive figure", the most recent national report on the subject says.
The report, by a working group of local authority and Scottish Office representatives, backed the idea of grouping schools with similar characteristics to provide a measure of expected progress against actual scores. But the concept could also be calculated in relation to all schools in Scotland, it states.
The education committee of the Convention of Scottish Local Authorities was today (Friday) expected to endorse continued work on the value-added initiative following the piloting of the concept in 18 primary schools (see above).
But the committee's watchword will be flexibility, with Cosla officials warning in advance of the meeting: "The initiative adopted a means of grouping schools and it was acknowledged that this requires to be handled carefully. "
The report stresses: "The grouping of schools is never rigid and, if any school can show that it has been wrongly placed, it can be allocated to a different group."
The focus will now shift to evaluating the primary 1 intake, since the trials only began with primary 3 classes, and extending the model into the early years of secondary school. But the report suggests the approach may have to be tested out in a larger sample of primary schools before this is done.
It comments: "Once the concept has been extended to English and mathematics in S1-S2, the S1-S2 model should be articulated with Standard grade analysis in S3-S4. It would also be necessary to revise the model currently used in S4-S5. The feasibility of electronic data collection direct from schools should also be investigated. If schools could submit data straight to the Scottish Office Education and Industry Department by disk or e-mail, then processing the data could be swift and ensure quick feedback to schools."
Although value-added measures are seen as an alternative to raw exam results, some experts warn against simplistic reliance on them to record an overall "school effect". In a critique of Government proposals for England issued in July, Harvey Goldstein of London's Institute of Education said: "A key finding of school effectiveness research is that schools are not uniformly effective or ineffective but differentially so for different groups of children, such as those from particular ethnic groups. More importantly, the research shows that many schools are differentially effective for initially low and initially high achieving children."
Professor Goldstein, in a study carried out for the Department for Education and Employment, claimed to show it was possible for each school to calculate separate value-added scores for the top 10 per cent of GCSE attainers and the bottom 10 per cent.
There was only "a moderate correlation" between them.