Although extensive research points to the potential payoffs from early childhood investments, much of the research is dated, has involved very small samples or has used less than rigorous research designs. As a result, there is a surprisingly thin body of evidence to guide specific decisions on how to design, target and implement public investments in preschools. Such investments have grown substantially over the last decade and more information is needed about how to ensure these investments pay off. This project is part of a larger venture designed to provide new and useful information to policy makers and others investing in public preschool regarding the approaches that are likely to lead to the most effective preschool programs. It will involve a large-scale literature review on 8-12 topical areas that a relevant to the implementation of public preschool programs. The findings from this literature review will be compared with the needs of localities who are implementing public preschool as a way to help identify avenues for future research.