One Year versus Two Years of an Enhanced Preschool Program: Impact on Academic and Cognitive Outcomes through Third Grade

Open Access
- Author:
- Shah , Harshini K
- Graduate Program:
- Human Development and Family Studies
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 23, 2011
- Committee Members:
- Mark T Greenberg, Dissertation Advisor/Co-Advisor
Mark T Greenberg, Committee Chair/Co-Chair
Celene E Domitrovich, Committee Member
Meg Leavy Small, Committee Member
Karen Linn Bierman, Committee Member
Michael John Cleveland, Committee Member
Lisa Michelle Kopp, Committee Member - Keywords:
- preschool dosage
longitudinal
academic
executive function
growth curve
disadvantaged - Abstract:
- A large body of evidence indicates the positive influence of preschool programming on child outcomes. However, few studies have examined the impact of attending one versus two years of preschool on children’s academic achievement and executive function (EF) skills even though such investigations could inform public policy and help dispense scarce resources in an efficient manner. This study assessed the differential benefit of attending one versus two years of an enhanced preschool program in Pennsylvania’s Harrisburg School District on 339 disadvantaged children’s academic (receptive vocabulary, reading and math) and EF (working memory and set-shifting) outcomes through third grade. As this study was quasi-experimental, propensity score modeling was utilized to control for selection biases between the two groups. Intercept differences from multi-level growth curve modeling (accounting for nesting by preschool classroom) revealed that two year attendees scored significantly higher on measures assessing reading at first grade, math at first and second grade and receptive vocabulary at first, second and third grade. On EF measures, two year attendees performed significantly better on measures assessing working memory at first and second grade and set-shifting at first, second and third grade. Multi-level growth curve models also indicated that two year attendees demonstrated better school readiness at kindergarten on all academic measures and differences in the slope revealed that they maintained this advantage until third grade on reading and receptive vocabulary. For math, one year attendees grew at a slightly faster rate after kindergarten and ‘caught up’ to the scores of the two year attendees by third grade. For EF, two year attendees demonstrated significantly higher working memory and set-shifting at first grade and this advantage was maintained over time. Also, regardless of preschool dosage, both groups were performing either at or within one standard deviation of the normative mean in elementary school. Results from latent class growth models demonstrated that attending preschool for two years significantly reduced the likelihood of membership in low performing trajectories on receptive vocabulary, math, working memory and set-shifting; this indicates that attending this enhanced preschool program for two years was especially beneficial for those who were most at risk of poor performance. Logistic regression was used to assess the impact of preschool dosage on grade retention and receipt of special education services. Combining these two sources assessing need for additional services, results demonstrated that two year attendees showed less need for additional services in elementary school; specifically, two year attendees were half as likely to be retained or to require special education services by third grade. In summary, participating in two years of enhanced preschool had a positive influence on child outcomes through third grade indicating that providing two years of high-quality preschool to at-risk children could be one way to reduce the achievement gap for disadvantaged children. The policy implications of these findings are discussed.