A critical meta-analysis of all evaluations of state-funded preschool from 1977 to 1998: Implications for policy, service delivery and program evaluation

The number of state-funded preschool programs for low-income children has increased dramatically over the past few decades, and recent research has indicated that these programs vary considerably along a variety of dimensions. By 1998 only 13 of the current 33 state preschool programs (which serve children 3 to 5, provide some form of classroom-based educational service, and are primarily funded and administered at the state level) had completed a formal evaluation of the program's impact on child outcomes. This paper presents a critical meta-analytic review of these evaluations, providing measures of standardized effects for all significant impacts to facilitate comparisons across differing domains of outcome and evaluative methods. Although several methodological flaws in these studies are identified, the pattern of overall findings may offer modest support for positive impacts in improving children's developmental competence in a variety of domains, improving later school attendance and performance, and reducing subsequent grade retention. Significant impacts were mostly limited to kindergarten and first grade; however, some impacts were sustained several years beyond preschool. The results of these studies were similar to evaluations of other large-scale preschool programs for low-income children, such as Head Start. Modest outcome goals are warranted for preschool programs serving low-income children, for example, the promotion of school readiness. Suggestions are presented for improved preschool and early intervention program evaluation.