„Ability grouping in school involves placing students into different classrooms or in small instructional groups in a class based on the students’ initial achievement or skill levels. Some research has shown that ability grouping can have a positive impact on the achievement of elementary school pupils, especially when there is mobility and flexibility in group allocations and when such grouping involves only specific subjects. […] On average across OECD countries in 2022, almost 4 in 10 students attended schools where students are grouped by ability into different classes for all subjects (7 %) or some subjects (31 %). The greatest incidence of this kind of grouping was observed in Ireland, Israel, Malta and the United Kingdom. In these countries/economies, at least nine in ten students attended a school that groups students into different classes for all or some subjects.“
OECD (Hrsg.), PISA 2022 Results, Vol.II. Learning During – and From – Disruption (2023), S. 157f.