The study took place within 21 school districts and 58 elementary schools in the state of Tennessee. Nineteen schools were in cities, 12 were in towns, 11 schools were in suburban areas, and 16 schools were in rural areas. Prekindergarten programs were operated through the school district, but actual services may have been provided through non-profit or for-profit child care providers, Head Start programs, or public schools.
As part of a larger evaluation of the Tennessee Voluntary Prekindergarten program (TN-VPK), the authors randomly offered enrollment in 76 TN-VPK classes with more applicants than they could enroll in the 2009–10 and 2010–11 school years. In this study (referred to as the “Intensive Substudy” by the study authors), the sample was limited to children from the larger evaluation who had parental consent for data collection and had outcome data at the end of the prekindergarten year (1,076 of the 3,025 children who were randomized). Using the Intensive Substudy sample, the authors employed a quasi-experimental design to compare children who had attended TN-VPK for 20 or more days to children who did not attend TN-VPK or attended fewer than 20 days. In the Intensive Substudy sample, children were 51.8 months (4 years, 4 months) of age on average at baseline; 48% were male; 23% were African American, and 19% were Hispanic; and 79% were native English speakers. The sample sizes varied by outcome and wave of measurement.
The intervention condition attended TN-VPK for 20 or more days. TN-VPK is a full-day program for 4-year-olds that operates on the same school-year calendar as the public school system in Tennessee. Enrollment is prioritized for students who are deemed as being at risk (i.e., eligible for free/reduced price lunch, English learners, children with disabilities, or “otherwise at risk”). The program must meet state board of education standards regarding teacher licensing, adult:student ratio, class size, and approved curriculum. The study authors stated that the 20-day threshold for attendance corresponds to a state enrollment standard.
The comparison group children did not attend TN-VPK or attended fewer than 20 days of TN-VPK. These children could have been cared for at home, received private childcare, attended Head Start, or attended another center-based preschool program.
Support for implementation
The state board of education standards for TN-VPK specify a licensed classroom teacher, at least one adult per 10 children, maximum class size of 20, and use of an approved curriculum. Non-school settings (e.g., private child care or Head Start) needed to meet these standards and hold the highest ratings from the Tennessee Department of Human Services licensing system. No additional information is provided about implementation of the program.