Co-Principal Investigators: Margaret Burchinal and Greg Duncan

Purpose: The purpose of the study is to learn whether the achievement gap separating children of low-income and higher income families can be substantially reduced by high quality preschool care alone, or whether preschool participation must be combined with high-quality infant/toddler care to reduce the gap. This research project will examine whether the advantages of preschool for school readiness differ depending on children's initial language and attention skills, and whether infant care followed by preschool has a greater effect on the economic achievement gap than either process alone.

Project Activities: The research team will use data from six data sets: National Head Start Impact Study (NHSIS), Early Head Start Study (EHSS), Infant Health and Development Program (IHDP), the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development (SECCYD), Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), and the National Center for Early Development and Learning 11-state pre-kindergarten study (NCEDL). The research team will conduct secondary data analyses to answer two key research questions: 1) do the effects of the type, quality, and quantity of preschool experiences vary by the level of cognitive/language and attention skills children exhibit when they begin preschool?; and 2) can the achievement gap separating children of low-income and higher income families be substantially reduced or eliminated by high-quality preschool care alone, or must such care be combined with high-quality infant/toddler care? The research team will identify relevant variables from each data set and conduct preliminary analyses during the first year of the study. Final data analyses and dissemination of the study findings will occur during year two of the project.

Products: Products include reports describing the association between aspects of the preschool program, child characteristics (language and attention skills), and children's school readiness at the start of kindergarten. The degree to which high-quality preschool and infant/toddler care contributes to reducing the achievement gap will also be discussed. The study findings will be disseminated in conference presentations and published reports.

Structured Abstract

Setting: The data to be analyzed will be drawn from six large-scale data sets: National Head Start Impact Study (NHSIS), Early Head Start Study (EHSS), Infant Health and Development Program (IHDP), the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development (SECCYD), Early Childhood Longitudinal Study-Birth Cohort (ECLS-B), and National Center for Early Development and Learning 11-state pre-kindergarten study (NCEDL).

Population: Characteristics of the data set samples are described here. The populations are diverse in nature and include over 21,000 infants and young children. The NHSIS data set includes a sample of 4,667 three- and four-year olds who were randomly assigned to receive Head Start services or to a control group (at home care or another type of child care). The EHSS sample includes 3,001 children less than 1 year of age who were randomly assigned to receive Early Head Start services, or to a control group (at home care or another type of child care). The IHDP study sample includes 985 low birth weight premature infants who were randomly assigned to medical follow-up or to a comprehensive early childhood intervention group immediately following hospital discharge. The SECCYD sampled newborns from hospital birth records from 10 sites in 9 states in 1991. At 36 months, the sample included 1,215 children. The SECCYD sample is disproportionately comprised of White, more highly educated mothers. The ECLS-B data set includes a nationally representative sample of children born in 2001. At preschool-age, the sample included 8,900 children. The ECLS-B sample includes children from a range of socioeconomic and racial/ethnic backgrounds. The NCEDL study sample includes 2,983 children enrolled in 704 pre-kindergarten classrooms in 11 states with public prekindergarten programs. These 11 states served approximately 80% of children in the United States who attended state pre-kindergarten programs in the study years of 2001-2003. About three-fourths of the pre-kindergarten programs were targeted to serve low-income children. Among the recruited children, 24% were African-American, 24% Latino/Hispanic, and 55% White. Fifty-five percent of the children came from families with incomes that qualified them for free or reduced-price lunches in schools.

Intervention: Not applicable.

Research Design and Methods: The research team will conduct secondary data analyses to understand the association between variation in child outcomes as a function of preschool experiences, children's school readiness and social/behavioral skills at preschool entry, and children's child care experiences in the years before preschool entry. Utilizing the six data sets, the research team will examine child outcomes (specific phonemic or numeric skills, language, attention, cognitive processes), children's functioning at age 3, home and child care experiences prior to age 3, and home and preschool experiences from age 3 to age 5 to consider why the effects of the preschool experience on school readiness at kindergarten entry vary so widely.

Control Condition: Not applicable.

Key Measures: Across six data sets, measures of academic achievement, language skills, learning-related behavioral skills, attention skills, parenting, and child-care quality were used. In addition, measures of classroom and home environment were collected.

Data Analytic Strategy: The research team will conduct comparable data analyses across the six data sets. They will estimate the effects of high-quality, academically oriented center-based preschool care on school readiness as children leave preschool for kindergarten. They will also test for differential effects for population subgroups defined by gender, social class, and race/ethnicity. They will estimate regression models for each research question. In their regression analyses, they will adjust for confounds by using measured control variables, propensity score matching techniques, and fixed effects when it is appropriate to do so.

Products and Publications

Journal article, monograph, or newsletter

Duncan, G.J., and Sojourner, A.J. (2013). Can Intensive Early Childhood Intervention Programs Eliminate Income-Based Cognitive and Achievement Gaps?. Journal of Human Resources, 48(4): 945–968.

Keys, T.D., Farkas, G., Burchinal, M.R., Duncan, G.J., Vandell, D., Li, W., and Ruzek, E.A., and Howes, C. (2013). Child Care/Preschool Quality and School Readiness: Quality Effects and Variation by Demographic and Child Characteristics. Child Development, 84(4): 1171–1190.

Li, W., Farkas, G., Duncan, G.J., Burchinal, M.R., and Vandell, D.L. (2013). Timing of High-Quality Child Care and Cognitive, Language, and Preacademic Development. Developmental Psychology, 49(8): 1440–1451.