by Marilyn Achiron
Editor, Directorate for Education and Skills
Successful education systems guarantee that all students succeed at high levels. As this month’s PISA in Focus notes, some school systems not only do well on international assessments, like PISA, they also manage to minimise the difference between the best- and poorest-performing students.
In some education systems, most students have similar levels of proficiency; in others, student performance varies far more widely. Analyses of PISA results show that countries and economies can achieve high average performance without having wide disparities in student performance. In 10 out of the 17 countries and economies that have above-average performance in reading, variations in student performance are smaller than the average variation observed across OECD countries.
PISA finds that 40% of the variation in student performance is found between schools within an education system. What accounts for that variation? A variety of factors. In Germany, large differences in the expected performance of students who attend different schools are related to the education systems’ policies of selecting students for different pathways through education, usually vocational or academic, based on students’ marks. In Italy, these variations are often related to differences in the profiles of the communities the schools serve, such as the socio-economic differences between students who attend urban schools and those who attend rural schools, and/or differences between the policies of federal and regional education systems. Variations can also be linked to characteristics of school systems that are more difficult to quantify, such as differences in the quality or the effectiveness of the instruction provided. Among high-performing countries, considerable between-school variation is found in only three countries: Belgium, Japan and the Netherlands. Between-school differences account for as little as 8% of the variation in student performance in Finland, 10% in Norway, and less than 20% in Estonia, Iceland and Poland.
PISA also tracks how variations in student performance have evolved over time. Across OECD countries, the average variation in student reading performance narrowed by 3% between 2000 and 2009, because most of the countries that improved their performance during that period did so by improving the performance of low-achieving students. Of the countries that saw improvements in performance during that period, only Poland recorded a marked decrease in between-school variation, while Sweden recorded a large increase.
We all know that students have different abilities, talents, interests and potentials (and vive la difference!). But the most successful and highest-performing school systems know how to elicit the best from every one of their students.