Preschool curricula are a much-researched topic in early childhood education and a renewed emphasis has been placed on understanding the effectiveness of curricula as the number of children enrolled in public preschool in the U.S. is increasing. Key to understanding how curricula are more or less effective in promoting classroom quality and children’s school readiness is knowing the differential relations between various packages that are used in public preschool classrooms, the extent to which these curricula are being implemented faithfully, and for whom they are most effective.

This dissertation, comprised of three studies, comprehensively examines the different ways in which various curricula promote children’s learning and development so that they are school-ready at the end of the preschool year. The first and second studies focus on whole-child curricula. For study one, I examine associations of various whole-child curricula packages on classroom quality and children’s school readiness outcomes using data from the Head Start Family and Child Experiences Survey, 2009 Cohort. Results suggest that the whole-child curricular packages under examination have no associations with improved classroom quality or children’s school readiness skills, including academic, socio-emotional, and executive function outcomes. In study two, I conduct open-ended observations of curriculum implementation fidelity across four classrooms located in Head Start centers to understand what a whole-child classroom looks like in practice. I find that teachers are able to implement easier, explicit components of the curriculum throughout the day as these activities are built into the daily classroom routine. However, I observe that teachers struggle with scaffolding children’s learning during these activities, which takes considerable skill on their part. Finally, in the third study I use quasi-experimental methods to explicitly test five different hypotheses of treatment effect heterogeneity in academic skill-specific curriculum interventions based on educational, developmental, and economic theory. Findings suggest that skill-specific curricula have differential effects at the top and bottom of the distribution of children’s literacy and language outcomes.

Together, the three studies provide new evidence that furthers the field’s understanding of curriculum as an important instructional feature in public preschools, both nationally and locally, and has implications for promoting the development of linguistically and culturally diverse low-income and disadvantaged children. These results provide policy-relevant information for facilitating the most efficient use of early learning funding, making decisions about how best to target specific curricular programs, and suggesting ways to improve the design and implementation of programs for high-quality preschool.