Within and Between School Variation in Achievement on the Programme for International Student Assessment (PISA) in Australia: PISA Australia Technical Paper

Australian secondary school students vary widely in their academic achievement. Using the scores from the Programme for International Student Achievement (PISA) in 2018, for example, the range from the 5th to the 95th percentile of student reading scores in Australia was 359 points compared to the OECD average of 327 points (OECD, 2019a; Thomson et al., 2019). This considerable range in achievement scores has been described as reflecting a long tail in the distribution of achievement. In this paper, attention is focused on the variation in the achievement scores of 15-year-old students in Australia based on data from PISA 2018. It explores the extent to which the variation in achievement arises from variation among students within schools or variation in average achievement between schools. The paper further explores the extent to which the variation in students’ attitudes to aspects of schooling, and their socioeconomic backgrounds, arise from differences within or between schools. The focus on looking at within and between school patterns is important - the proportion of the variance in student achievement that occurs between schools can be interpreted as a measure of vertical or academic inclusion (Willms, 2010). At the same time, large variance within schools has important implications for approaches to teaching, specifically with relation to differentiation. Understanding the patterns thus illustrates themes of great salience for the Australian education system.