WWC Review of a Recent Study of Full-Day vs. Part-Day Preschool

What is the study about?
This study examined whether children enrolled in a full-day preschool program scored higher on school readiness measures and had higher attendance rates than children who attended the same schools but participated in the part-day preschool program. The programs were part of an expansion and update of the Child-Parent Center (CPC) Education Program, a long-standing school-based program that combines comprehensive education and family services and had previously been implemented as a part-day program only. This study focused on 11 schools in Chicago that implemented both the full-day and part-day updated versions of the CPC programs.

What did the study report?
The authors reported that children participating in a full-day program scored higher than children in a part-day program, by a statistically significant margin, on four of the six school readiness indicators from the standardized Teaching Strategies GOLD Assessment System, including language, math, social-emotional development, and physical health. The authors also reported statistically significant improvements in attendance.

How does the WWC rate this study?
The study uses a quasi-experimental design to compare the performance of children in the intervention (full-day) and comparison (part-day) groups. However, in the main analysis, groups were not equivalent at the start of the intervention. When children were selected to participate in the full-day program, 4-year-olds were given priority over 3-year-olds, so the groups, on average, are not equivalent. Therefore, because the groups in this main analysis are not equivalent, the study does not meet WWC group design standards.

In addition to the main analysis, the authors present analyses based on subgroups of children of similar age. These analyses could meet WWC group design standards with reservations if the groups were comparable at baseline. However, the authors did not present equivalence information. Therefore, because the main analysis comparing 4 year-olds in full-day kindergarten and 3 year-olds in the part-day program does not meet WWC group design standards, the WWC will not request information to determine the rating for analyses of age-specific subgroups.

Citation
Reynolds, A. J., Richardson, B. A., Hayakawa, M., Lease, E. M., Warner-Richter, M., Englund, M. M., Ou, S. R., & Sullivan, M. (2014). Association of a full-day vs part-day preschool intervention with school readiness, attendance, and parent involvement. JAMA, 312(20), 2126–2134. doi: 10.1001/jama.2014.15376

The WWC conducts quick reviews of studies that have received significant media attention. This study was mentioned in Bloomberg, The Chicago Sun Times, Education Week, The Huffington Post, Minnesota Daily, and US News.