Exclusive: Pisa data may be incomparable, Schleicher admits

Falls in Asian high-flyers' math scores could simply be down to switch to computer tests.


The man running the world’s most influential education study has admitted that seemingly dramatic changes in performance for top-ranked countries shown by its “comparable data” could, in fact, be explained by changes to the way its tests are delivered.


According to the latest Programme for International Student Assessment (Pisa) study from 2015, the global top-ranked performers in maths have all seen falls in the percentage of their pupils achieving high test scores in the subject over the previous three years.


That apparent decline in the ability of East Asian maths superpowers to stretch the brightest could have wider implications. Schools in the US and the UK have invested heavily in emulating the Asian maths “mastery” approach.