The questions of whether preschool children benefi t more strongly when early care and education (ECE) is at or above a threshold of quality, has specifi c quality features, and/or is of longer duration were examined in secondary data analyses of eight large ECE studies. These issues are pivotal in recent ECE policies designed to improve school readiness skills, especially for children from low-income families. Threshold analyses examined whether quality had stronger associations with gains in child outcomes in settings with high levels of quality than those with lower quality. Features...