The purpose of this paper is to present high-level findings and trends from a review of the literature and discussions with experts on the quality of early learning in center-based early care. This review focuses primarily on children from low-income families. This work addresses seven questions: - What level of quality must early learning deliver in order to achieve improved school-readiness outcomes for children? - Is there an upper threshold beyond which increasing the quality of early learning stops producing increasing results? - Do the immediate benefits of high-quality early learning always fade-out? - Does having children spend more time in early learning programs yield any benefits? - Do children in low-income families benefit more from high-quality early learning than their more advantaged peers? - What are the features and environments that constitute high-quality early learning? - Is the relationship between the quality of early learning programs and school readiness linear? Does it matter? What are the implications for increasing school readiness in Washington? (author abstract)