This Research-to-Policy, Research-to-Practice brief series focuses on issues related to the development and refinement of measures to assess the quality of early childhood and school age care settings. Introduction: States and the federal government have invested in early care and education programs with an explicit goal of improving school readiness for low-income children. These investments, aimed at strengthening the quality of care and supporting families’ access to high-quality settings, are based in part on a confluence of research findings showing a link between program quality and children’s outcomes. Specifically: -Studies of model programs demonstrate that intensive early childhood services delivered over a period of years can improve children’s cognitive, academic, and social skills with gains maintained into adulthood. -Larger and more representative descriptive studies suggest that the effects of early care and education, while smaller than family effects, can be maintained when children go to school. While research to date is quite consistent in showing that measures of quality in early care and education settings and measures of children’s development are linked when examined in individual research studies, there has not been a systematic examination of the strength of these relationships across multiple studies. This brief examines this.