ECE quality indicators and child outcomes: Analyses of six large child care studies

•Developmental theory suggests that children develop within complex systems, but most research on ECE focuses on discrete aspects of quality.•This study uses a framework common in ECE policy to examine the association between ECE quality defined by multiple indicators and child outcomes.•Replicated analyses were conducted with six large studies of ECE quality to relate structural and quality indicators to child outcomes.•Small gains in child outcomes were observed related to quality of teacher–child interactions, curriculum, and teacher and director education.•Combining quality indicators into a single index also predicted gains in preschoolers’ language and literacy scores, but effect sizes were small.