Research Report

Is More Better? The Effects of Full-Day vs Half-Day Preschool on Early School Achievement


The positive effects of high-quality early education found for cognitive, linguistic, social, and economic outcomes has led to substantial public investment in preschool programs for economically disadvantaged children. An important question in the design of public preschool programs is whether learning increases as time in preschool is increased.

The results of a randomized trial comparing the effects of extended-day, extended-year public preschool to half-day preschool on children’s literacy and mathematics learning are presented in this report. The authors found that children who attended an extended-day, extended-year preschool program experienced greater improvement in test scores compared to peers who attended half-day programs.

While the results clearly indicate that duration and intensity matter, the authors recommend further research is needed to augment this single study of half-day vs. extended-day preschool.

The Authors

In her work, Dr. Frede applies what she has learned throughout her varied career in early childhood education, including experience as a teacher of ages 0-8, curriculum and professional development specialist at the HighScope Foundation, teacher educator at The College of New Jersey, researcher, pre-k administrator for the New Jersey Department of Education, education lead in a large Head Start grantee and early learning lead at the Bill and Melinda Gates Foundation. 

W. Steven (Steve) Barnett is a Board of Governors Professor and the founder and Senior Co-Director of the National Institute for Early Education Research (NIEER) at Rutgers University. Dr. Barnett’s work primarily focuses on public policies regarding early childhood education, child care, and child development.