A compositional effect is when pupil attainment is associated with the characteristics of their peers, over and above their own individual characteristics. Pupils at academically selective schools, for example, tend to out-perform similar-ability pupils who are educated with mixed-ability peers. Previous methodological studies however have shown…

Data has played an important role in England's recent school improvement journey. The evolution of the approach has not been perfect but the National Pupil Database has become a vital tool for health checking the education system, driving accountability, directing education policymaking, and tracking the educational attainment of key vulnerable…