This report synthesises the findings from 2 rigorous literature reviews entitled: The role and impact of private schools in developing countries, and The role and impact of philanthropic and religious schools in developing countries. It aims to bring together and compare and contrast key findings from the 2 reviews, and to identify areas of research needed to fill gaps in the knowledge base on non-state schools, in an attempt to contribute to working towards a more evidence informed approach to policy in this area.