Summary of Results from Vanderbilt’s Pre-K Study

Below is an excerpt from the Executive Summary of Vanderbilt University’s Peabody College study of prekindergarten in Tennessee.

The research report was released Sept. 28, 2015. It is titled, “A Randomized Control Trial of a Statewide Voluntary Prekindergarten Program on Children’s Skills and Behaviors through Third Grade.”

Summary of results. Results from this first randomized control trial of a state funded targeted pre‐k program delivered at scale are complex. We focused our research on three primary questions.

The first question concerned the effectiveness of the TN‐VPK program at preparing children for kindergarten entry. At the end of pre‐k, the TN‐VPK children had significantly higher achievement scores on all 6 of the subtests, with the largest effects on the two literacy outcomes. The effect size on the composite achievement measure was .32. This effect is of the same magnitude as Duncan and Magnuson (2013) reported for end of treatment effects for all pre‐k programs and larger than the average of programs enacted since the 1980s. At the beginning of kindergarten, the teachers rated the TN‐VPK children as being better prepared for kindergarten work, as having better behaviors related to learning in the classroom and as having more positive peer relations. They did not view the children as having more behavior problems and both groups of children were rated as being highly positive about school.

The second question addressed was whether subgroups of children were differentially affected by TN‐VPK attendance. We examined a number of possible moderators of the pre‐k effects and found no relationships for gender, ethnicity, or age of enrollment. The moderators we did find were driven by interactions involving mothers’ education and children who at age 4 did not speak English. The TN‐VPK effects were the largest for children who were learning English and whose mothers had less than a high school degree. English language learners with more educated mothers had the next largest effect size. The effects for native English speakers whether or not their mothers had a high school degree were considerably lower.

The third question we addressed involved the sustainability of effects on achievement and behavior beyond kindergarten entry. Children in both groups were followed and reassessed in the spring every year with over 90% of the initial sample located tested on each wave. By the end of kindergarten, the control children had caught up to the TN‐VPK children and there were no longer significant differences between them 5 on any achievement measures. The same result was obtained at the end of first grade using both composite achievement measures.

In second grade, however, the groups began to diverge with the TN‐VPK children scoring lower than the control children on most of the measures. The differences were significant on both achievement composite measures and on the math subtests. The moderating effects of ESL status and mothers’ education were no longer significant, but it is interesting to note that whether or not ESL children experienced TN‐VPK, by the end of third grade, their achievement was greater than either of the native English speaking groups of children.

In terms of behavioral effects, in the spring the first grade teachers reversed the fall kindergarten teacher ratings. First grade teachers rated the TN‐ VPK children as less well prepared for school, having poorer work skills in the classrooms, and feeling more negative about school. It is notable that these ratings preceded the downward achievement trend we found for VPK children in second and third grades. The second and third grade teachers rated the behaviors and feelings of children in the two groups as the same; there was a marginally significant effect for positive peer relations favoring the TN‐VPK children by third grade teachers.

Conclusion. The TN‐VPK program saturates the state; every county has at least one classroom and all school districts except one have endorsed the program by opening new classrooms. Thus, the structural support exists in the state to continue to explore pre‐k as a means for preparing children for success in school, but we need to think carefully about what the next steps should be. It is apparent that the term pre‐k or even “high‐quality” pre‐ k does not convey actionable information about what the critical elements of the program should be. Now is the time to pay careful attention to the challenge of serving the country’s youngest and most vulnerable children well in the pre‐k programs like TN‐VPK that have been developed and promoted with their needs in mind.