Background This study aimed at assessing the impact of including children with intellectual disability (ID) in general education
classrooms with support on the academic achievement of their low-, average-, and high-achieving peers without disability.
Method A quasi-experimental study was conducted with an experimental group of 202 pupils from classrooms with an
included child with mild or moderate ID, and a control group of 202 pupils from classrooms with no included children
with special educational needs (matched pairs sample). The progress of these 2 groups in their academic achievement was
compared over a period of 1 school year.
Results No signifi cant difference was found in the progress of the low-, average-, or high-achieving pupils from classrooms
with or without inclusion.
Conclusions The results suggest that including children with ID in primary general education classrooms with support
does not have a negative impact on the progress of pupils without disability.