The increasing trend of placing students with disabilities in general education classrooms has raised questions among researchers, policymakers, practitioners, and parents about classmate peer effects on all students. However, little is known about the peer effects of classmates with disabilities on the outcomes of other students in the classroom;…

We evaluate the impact of Success for All literacy instruction in grades 3 through 5 using data from the same cluster randomized trial used to evaluate effects in the earlier grades (K-2). In contrast to the early benefits, there is no effect on reading achievement in the later grades, either overall or for students and schools with high or low…

Kindergarten mathematics skills are important for subsequent achievement, yet mathematics is underemphasized in kindergarten classrooms. Using nationally representative data, this study explored the relationship between students' school-entry math skills, classroom content coverage, and end-of-kindergarten math achievement. Although the vast…

We use two nationally representative data sets to estimate the prevalence of kindergarten "redshirting"--the decision to delay a child's school entry. We find that between 4% and 5.5% of children delay kindergarten, a lower number than typically reported in popular and academic accounts. Male, White, and high-SES children are most…

We contribute to debate about causal inferences in educational research in two ways. First, we quantify how much bias there must be in an estimate to invalidate an inference. Second, we utilize Rubin's causal model to interpret the bias necessary to invalidate an inference in terms of sample replacement. We apply our analysis to an inference…

This study challenges the belief that homogeneous ability grouping benefits high-ability students in cognitive and social-emotional development at the expense of their low-ability peers. From a developmental point of view, the authors hypothesize that homogeneous grouping may improve the learning behaviors and may benefit the literacy learning of…

This article reports the outcomes of a multiyear study comparing the English and Spanish language and reading performance of Spanish-dominant children randomly assigned, beginning in kindergarten, to transitional bilingual education (TBE) or structured English immersion (SEI) for periods of up to 5 years. On the Peabody Picture Vocabulary Test and…

Over the past 70 years, all states in the United States began to publicly subsidize kindergarten using state revenue. The variation in adoption dates across states allows for a unique opportunity to measure the effectiveness of the largest early education program implemented in recent history. The significant, immediate increase in the…

A kindergartner's opportunities to develop reading and language arts skills are constrained by the amount of time allocated to reading instruction. In the meantime, the student's engagement in learning tasks may increase if the instruction has been adapted to his or her prior ability through homogeneous grouping. This study investigates whether…

Ability grouping is sometimes thought to exacerbate inequality by increasing achievement gaps; however, ability grouping may in fact benefit a fast growing and often marginalized student population: children from non-English-speaking home environments. The level-appropriate, small-group instruction received in reading ability groups may be…

Successful implementation of evidence-based educational practices at scale is of great importance but has presented significant challenges. In this article, the authors address the following questions: How does the level of on-site technical assistance affect student outcomes? Do teachers' fidelity of treatment implementation and their perceptions…

The debates over the 2003 reauthorization of Head Start highlighted a controversy about the devolution of federal early education policy. At the center of the debate is the concern that state control of early education programs will reduce the quality and effectiveness of federal support for children living in poverty, and their families. The…

The appropriate age for students to begin school is an issue of debate for educators, administrators, and parents. Parents worry that young children may not be able to compete with older classmates; schools worry that young students will not be able to meet rigorous academic standards associated with school accountability. Past literature is…

Although experimental results indicate that smaller classes promote higher achievement in early elementary school, the broader literature on class-size effects is inconclusive. This seeming contradiction raises questions about the generalizability of experimental evidence, an issue that this article addresses by examining the effects of class size…

The present study was designed to examine the relationship between performance on a standards-based assessment of reading comprehension in fourth grade and performance on a diagnostic battery of component skills of reading for a cohort of children who were followed from kindergarten through fourth grade. The findings demonstrate that the…