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.