The Department of Education commissioned the Education and Training Inspectorate to carry out an evaluation of the impact of SEN provision in mainstream schools and support on pupil outcomes, with a particular focus on effective early intervention strategies. Twenty primary schools and ten post-primary schools which had been evaluated previously through ETI inspections and district visits as having highly effective provision for pupils with SEN were selected for an evaluation. The schools in the survey have developed a comprehensive variety of systems and strategies to provide competently for these pupils. Part one of the survey identifies common factors which have proven to ensure a high quality mainstream school provision for pupils with SEN, and part two of the survey has 30 case studies of the effective practice in the schools visited.