This is accurate in relation to the 80 Scottish primary and secondary schools and some 7,000 pupils in the Improving School Effectiveness Project (ISEP). The key phrase is "up to one-third" of the variance. This refers to pupil progress across a range of curriculum-based measures.
The research cited by Dr Croxford as comparable with ISEP in fact involved only 20 schools in one authority. It used the verbal reasoning quotient (VRQ), only one outcome measure and refers to students who left school in 1984. The author himself notes that his sample was not large enough to identify much variation in school effects. Even so he concluded that "even for a pupil of given gender, VRQ and SES (socio-economic status), the expected attainment in public examinations could depend to an educationally significant extent on the school attended".
We should also draw attention to our emphasis that ISEP found, in common with other research, that by far the strongest influence on pupil progress consists of a combination of prior attainment and pupil background factors, but that schools are none the less important.
Our contribution to "Raising Standards - Setting Targets" provides a broad research context for the Scottish Office initiative. The Audit Unit publication of the summary findings is exactly as supplied by us. If there is an ambiguity in interpretation, it is due to our own attempt to summarise complex issues in a concise and accessible form. There are many ISEP papers already in the public domain which give a fuller and more detailed account of the school effect. A complete summary will be published shortly and available at our Edinburgh conference on October 28.
John MacBeath. Director. Quality in Education Centre. Strathclyde University. Peter Mortimore. Director. Institute of Education. London University