As the public profile of early childhood education has increased, state education agency staff, policymakers, and researchers are interested in understanding the lasting impacts of quality pre-K. Particularly for states beginning an investment in early childhood education or expanding access to an existing program, it is important to examine the research base for what type and the intensity of impacts policy makers can expect to see in subsequent years of schooling for children who participated in prekindergarten. It is also important to identify the factors that contribute to children experiencing high-quality prekindergarten and to understand what is known about how likely it is that these effects are expected to lead to lasting positive outcomes. (author abstract)