How Large are Secondary School Effects in Northern Ireland?

This study is concerned with estimates of secondary school effect size in Northern Ireland. Utilising data from a random sample of the region's schools, four indices of pupil achievement variation in public examinations are employed. These outcome measures are (i) overall examination achievement - a composite weighted measure - together with achievement in General Certificate of Education examinations in (ii) English, (iii) Mathematics and (iv) Chemistry. Examinations of this type are taken, typically, by pupils aged 16 years (the statutory leaving age), at the end of their fifth year of secondary education. Using a two-level hierarchical linear regression model, the paper considers variation in school effect size by outcome criterion. Variation is measured in standard deviation units and in terms of the proportion of achievement variance "explained" by schools after adjustment for pupil-intake differences. Comparisons are made with recent findings for Scotland and for England. [ABSTRACT FROM AUTHOR]