Investigating if high-quality kindergarten teachers sustain the pre-K boost to children's emergent literacy skill development in North Carolina.

This study tested the hypothesis that high-quality kindergarten teachers sustain and amplify the skill development of children who participated in North Carolina's NC Pre-K program during the previous year, compared to matched non-participants (N = 17,330; 42% African American, 40% Non-Hispanic White, 15% Hispanic; 51% male; Mage = 4.5 years at fall of pre-K). Kindergarten teacher quality was measured using a "value-added" approach. NC Pre-K participants outperformed non-participants in the fall of kindergarten (ß = .22) and 11% of this boost remained evident by the spring of kindergarten. Higher value-added teachers promoted the skill development of all children (ß = .30 in the spring) but did not differentially benefit the skill development of former NC Pre-K participants compared to non-participants.

Can Peers Help Sustain the Positive Effects of an Early Childhood Mathematics Intervention?

Our study assessed whether the peer environment in kindergarten and first grade affected student learning following an early mathematics intervention. We leveraged longitudinal data from a cluster-RCT to examine whether math achievement in kindergarten (n = 1,218) and first grade (n = 1,126) was affected by either the share of high-achieving classmates or the proportion of classroom peers who received a preschool math curriculum intervention. Analyses indicated that exposure to treated peers in first grade, but not kindergarten, was significantly associated with small gains in end-of-year achievement. Some analyses also suggested that average peer math achievement was generally positively related to children's kindergarten and first-grade achievement across conditions, though these results were less robust. We did not find consistent evidence to suggest that the proportion of treated peers coincided with better teaching practices. Taken together, these findings suggest that classroom peer effects may play only a limited role in sustaining early intervention effects.

Understanding Heterogeneity in the Impact of Public Preschool Programs.

We examine the North Carolina Pre-K (NC Pre-K) program to test the hypothesis that observed variation in effects resulting from exposure to the program can be attributed to interactions with other environmental factors that occur before, during, or after the pre-k year. We examine student outcomes in 5th grade and test interaction effects between NC's level of investment in public pre-k and moderating factors. Our main sample includes the population of children born in North Carolina between 1987 and 2005 who later attended a public school in that state, had valid achievement data in 5th grade, and could be matched by administrative record review (n = 1,207,576; 58% White non-Hispanic, 29% Black non-Hispanic, 7% Hispanic, 6% multiracial and Other race/ethnicity). Analyses were based on a natural experiment leveraging variation in county-level funding for NC Pre-K across NC counties during each of the years the state scaled up the program. Exposure to NC Pre-K funding was defined as the per-4-year-old-child state allocation of funds to a county in a year. Regression models included child-level and county-level covariates and county and year fixed effects. Estimates indicate that a child's exposure to higher NC Pre-K funding was positively associated with that child's academic achievement 6 years later. We found no effect on special education placement or grade retention. NC Pre-K funding effects on achievement were positive for all subgroups tested, and statistically significant for most. However, they were larger for children exposed to more disadvantaged environments either before or after the pre-k experience, consistent with a compensatory model where pre-k provides a buffer against the adverse effects of prior negative environmental experiences and protection against the effects of future adverse experiences. In addition, the effect of NC Pre-K funding on achievement remained positive across most environments, supporting an additive effects model. In contrast, few findings supported a dynamic complementarity model. Instrumental variables analyses incorporating a child's NC Pre-K enrollment status indicate that program attendance increased average 5th grade achievement by approximately 20% of a standard deviation, and impacts were largest for children who were Hispanic or whose mothers had less than a high school education. Implications for the future of pre-k scale-up and developmental theory are discussed.

Boosting School Readiness: Should Preschool Teachers Target Skills or the Whole Child?

We use experimental data to estimate impacts on school readiness of different kinds of preschool curricula - a largely neglected preschool input and measure of preschool quality. We find that the widely-used "whole-child" curricula found in most Head Start and pre-K classrooms produced higher classroom process quality than did locally-developed curricula, but failed to improve children's school readiness. A curriculum focused on building mathematics skills increased both classroom math activities and children's math achievement relative to the whole-child curricula. Similarly, curricula focused on literacy skills increased literacy achievement relative to whole-child curricula, despite failing to boost measured classroom process quality.

Complementarities between Early Educational Intervention and Later Educational Quality? A Systematic Review of the Sustaining Environments Hypothesis.

The sustaining environments hypothesis refers to the popular idea, stemming from theories in developmental, cognitive, and educational psychology, that the long-term success of early educational interventions is contingent on the quality of the subsequent learning environment. Several studies have investigated whether specific kindergarten classroom and other elementary school factors account for patterns of persistence and fadeout of early educational interventions. These analyses focus on the statistical interaction between an early educational intervention - usually whether the child attended preschool - and several measures of the quality of the subsequent educational environment. The key prediction of the sustaining environments hypothesis is a positive interaction between these two variables. To quantify the strength of the evidence for such effects, we meta-analyze existing studies that have attempted to estimate interactions between preschool and later educational quality in the United States. We then attempt to establish the consistency of the direction and a plausible range of estimates of the interaction between preschool attendance and subsequent educational quality by using a specification curve analysis in a large, nationally representative dataset that has been used in several recent studies of the sustaining environments hypothesis. The meta-analysis yields small positive interaction estimates ranging from approximately .00 to .04, depending on the specification. The specification curve analyses yield interaction estimates of approximately 0. Results suggest that the current mix of methods used to test the sustaining environments hypothesis cannot reliably detect realistically sized effects. Our recommendations are to combine large sample sizes with strong causal identification strategies, and to study combinations of interventions that have a strong probability of showing large main effects.

Do High-Quality Kindergarten and First-Grade Classrooms Mitigate Preschool Fadeout?

Prior research shows that short-term effects from preschool may disappear, but little research has considered which environmental conditions might sustain academic advantages from preschool into elementary school. Using secondary data from two preschool experiments, we investigate whether features of elementary schools, particularly advanced content and high-quality instruction in kindergarten and first grade, as well as professional supports to coordinate curricular instruction, reduce fadeout. Across both studies, our measures of instruction did not moderate fadeout. However, results indicated that targeted teacher professional supports substantially mitigated fadeout between kindergarten and first grade but that this was not mediated through classroom quality. Future research should investigate the specific mechanisms through which aligned preschool-elementary school curricular approaches can sustain the benefits of preschool programs for low-income children.