School-to-school collaboration has been central to many improvement efforts over recent decades. In an attempt to promote both improvement and equity current developments in England have included changing formal governance arrangements to promote collaboration for improvement through "federations" and "chains" of schools.…

This study adopted a quantitative methodology involving a matched sample of federated and non-federated schools and utilising multilevel modelling techniques to explore the impact of federations on student outcomes. The sample involves a total of 50 school districts and 264 schools. These are grouped into 122 federations; 264 comparator schools…