Few rigorous studies of the effectiveness of contemporary public prekindergarten programs have been conducted despite the growing number of programs and large monetary investments they require. The study on which this presentation is based was launched in collaboration with the Tennessee State Department of Education to provide an assessment of the statewide Tennessee Voluntary Prekindergarten (TN-VPK) program on the economically disadvantaged population it serves. Across two cohorts, 80 different schools in 29 Tennessee school districts with more applicants than they could accommodate submitted applicant lists from which 3171 children were randomly assigned to participate or not in TN-VPK. Of those, 1076 consented children (773 TN-VPK; 303 nonparticipants) have been individually assessed at the beginning and end of pre-k, end of kindergarten, and end of first grade in an intensive substudy.

The children in TN-VPK attended an average of 149 days during the school year while 60% of the children who were not admitted to TN-VPK stayed home and 27% enrolled in Head Start or private center-based childcare. During the pre-k school year, the children who participated in TN-VPK gained significantly more than children who did not attend on Woodcock Johnson III measures of literacy, language, and math skills, with effect sizes ranging from .12 to .46. Positive effects were also found on the kindergarten teachers’ ratings of children’s preparedness for kindergarten, children’s classroom work behavior, and their social behavior.

Follow-up assessments at the end of kindergarten, first grade, and second grade, however, showed that the effects on the achievement outcomes were not sustained. On the other hand, some indications appeared of better outcomes emerging for the TN-VPK group on grade retention and attendance. Outcome data on special education and English language designations, along with formal disciplinary actions, will also be available by the time of this presentation. Discussion of these results will focus on the difference between short-term and long-term effects of pre-k and hypotheses about why some pre-k effects may not be sustained and others may emerge well after the end of the pre-k year. Meanwhile, the study continues and will follow the participating children through middle school to further assess the long-term effects of TN-VPK.