I WISH to comment on the letter (TESS, September 18) from John MacBeath and Peter Mortimore. Firstly, I agree with Linda Croxford's letter the previous week. When the HMI Audit Unit quoted figures from the Improving School Effectiveness Project (ISEP) this was clearly done to bolster the case for the method of target setting involving free school meals uptake. To quote primary school findings in this context certainly misled me.
MacBeath and Mortimore criticise the research by Croxford which shows a much lower variance (only 1.1 per cent) in attainment attributable to "school factors" than the ISEP study. I am uneasy about one aspect of the excellent ISEP policy papers - control over the influence of level of parental education and current occupation.
I realise these variables are highly correlated with measures for free school meals and numeracy and literacy carried out in S2. The worry remains, however, that some variance for Standard grade results which is attributed to school factors really belongs to factors of home background.
I believe we need some measure of home background advantage as well as disadvantage. The advantage effect could be significant in Standard grade and Higher grade statistics even after controlling for free school meals and attainment in S1 and S2.
The need for a measure of advantage is certainly reinforced by the fact that schools with a highly "advantaged" profile are highly ranked not only in "raw" Standard grade league statistics, but also almost always do well in terms adjusted statistics of free school meals .
Michael Davenport Bank Road, East Linton