There are unique challenges to estimating causal effects of preschool for students with special needs that have not received attention in the literature. We revisit the Head Start Impact Study (HSIS) to illustrate that when and how special needs is defined has implications for the internal validity of and interpretation of special needs subgroup…

This study uses data from a comprehensive database of U.S. early childhood education program evaluations published between 1960 and 2007 to evaluate the relationship between class size, child-teacher ratio, and program effect sizes for cognitive, achievement, and socioemotional outcomes. Both class size and child-teacher ratio showed nonlinear…

This study explores the extent to which differences in research design explain variation in Head Start program impacts. We employ meta-analytic techniques to predict effect sizes for cognitive and achievement outcomes as a function of the type and rigor of research design, quality and type of outcome measure, activity level of control group, and…

This study is a randomized controlled trial that assessed the impact of Early College High Schools on students' high school graduation, college enrollment, and college degree attainment, as well as students' high school experiences using extant data and survey data. The study included 10 Early Colleges that enrolled students in Grades 9 to 12 in…

This article presents findings from a lottery-based study of the impacts of a broad set of 33 charter middle schools across 13 states on student achievement. To estimate charter school impacts, we compare test score outcomes of students admitted to these schools through the randomized admissions lotteries with outcomes of applicants who were not…

This article presents the findings of an evaluation of the eMINTS (enhancing Missouri's Instructional Networked Teaching Strategies) professional development program. eMINTS is an intensive teacher professional development program designed to promote inquiry-based learning, support high-quality lesson design, build community among students and…

Stereotype threat is frequently purported to be an important determinant of gender gaps in math. Unlike prior studies, which mostly occur in lab settings, I use data from the National Assessment of Educational Progress (NAEP)--a large, representative assessment of U.S. children--where through a design quirk, students are randomly assigned test…

This study exploits a randomized trial of two light-touch elementary school interventions to estimate long-run impacts on postsecondary attendance and attainment. The first is a classroom management technique for developing behavioral skills in children. The second is a curricular intervention aimed at improving students' core reading skills. We…

This paper provides practical guidance for researchers who are designing and analyzing studies that randomize schools--which comprise three levels of clustering (students in classrooms in schools)--to measure intervention effects on student academic outcomes when information on the middle level (classrooms) is missing. This situation arises…

The authors describe an independent evaluation of the READ 180 Enterprise intervention designed by Scholastic, Inc. Despite widespread use of the program with upper elementary through high school students, there is limited empirical evidence to support its effectiveness. In this randomized controlled trial involving 312 students enrolled in an…

Although closure is an increasingly common response to the problems of chronically underperforming urban schools, few studies have examined the effect of closure on displaced students. The authors used multiple methods to study the academic performance and experiences of Latino and African American high school students in the year following the…

By offering information, counseling, and tutoring, college outreach programs attempt to smooth the path between high school and higher education for at-risk students. But do these program work? This paper uses longitudinal data from the Education Longitudinal Study to construct two quasi-experiments to assess the effectiveness of college outreach.…

Interest has rapidly increased in studies that randomly assign classrooms or schools to interventions. When well implemented, such studies eliminate selection bias, providing strong evidence about the impact of the interventions. However, unless expected impacts are large, the number of units to be randomized needs to be quite large to achieve…

This paper presents a new technique in which covariates are controlled and evaluation data still are presented graphically in a manner that makes sense to policy makers. An illustration is provided using data drawn from an evaluation by the author of a major National Science Foundation (NSF) university funding program. (Author)

This article examines how controlling statistically for baseline covariates, especially pretests, improves the precision of studies that randomize schools to measure the impacts of educational interventions on student achievement. Empirical findings from five urban school districts indicate that (1) pretests can reduce the number of randomized…