A quasi-experimental study of a novel, cross-content area vocabulary intervention program called "Word Generation" showed significantly greater growth among 6th- to 8th-grade students in schools implementing the program than in comparison schools, on a curriculum-specific test. Furthermore, the language-minority students in the treatment, but not…

The goal of this study was to assess the effectiveness of an intervention--Quality English and Science Teaching (QuEST)--designed to develop the science knowledge and academic language of middle grades English language learners studying science in their second language and their English-proficient classmates. Ten sixth-grade science teachers in 5…

Expanded instructional time has become increasingly popular as a strategy to improve the academic outcomes of low-skilled students, particularly in the 9th grade. We evaluate the efficacy of a double-period algebra policy initiated in the Chicago Public Schools in 2003. This policy required all students with 8th-grade test scores below the…

The purpose of this research was to explore the relative effectiveness of intensive reading interventions for struggling high school readers. A yearlong randomized control study was conducted to estimate causal effects, as measured by the criterion-referenced state assessment test, for 1,265 ninth-grade students in 89 classes across 7 high schools…

Two experimental studies to improve vocabulary knowledge and comprehension were conducted in 7th-grade social studies classes with English language learners (ELLs). Two different nonoverlapping samples of classes of 7th-grade students (N = 381 and N = 507) were randomly assigned at the classroom (i.e., section) level to a social studies…

Two complementary approaches to developing empirical benchmarks for achievement effect sizes in educational interventions are explored. The first approach characterizes the natural developmental progress in achievement made by students from one year to the next as effect sizes. Data for seven nationally standardized achievement tests show large…

Experiments that involve nested structures may assign treatment conditions either to subgroups (such as classrooms) or individuals within subgroups (such as students). The design of such experiments requires knowledge of the intraclass correlation structure to compute the sample sizes necessary to achieve adequate power to detect the treatment…

This article describes 1st-year experimental effects of a large-scale reform providing professional development to elementary school teachers to implement an extended, inquiry-oriented science curriculum. Known as "immersion teaching" because it "immerses" teachers and students in the full cycle of scientific inquiry, this approach developed…

This study examines the reporting of power analyses in the group randomized trials funded by the Institute of Education Sciences from 2002 to 2006. A detailed power analysis provides critical information that allows reviewers to (a) replicate the power analysis and (b) assess whether the parameters used in the power analysis are reasonable.…

We provide data 3 to 4 years postintervention for four samples of English language learners from two sequential Grade 1 cohorts who received supplemental Grade 1 reading interventions in Spanish or English and for whom the language of instruction for intervention was matched with language of core reading instruction. Participants were 300 students…

A dramatic shift in research priorities has recently produced a large number of ambitious randomized trials in K-12 education. In most cases, the aim is to improve student academic learning by improving classroom instruction. Embedded in these studies are theories about how the quality of classroom must improve if these interventions are to…

Many postsecondary institutions utilize learning communities to increase social engagement and attachment to the college community. In recent years, these communities have proliferated as part of a trend fueled by low retention and persistence rates, increasing reluctance of 4-year institutions to provide remedial education, and pressure on…

Research indicates that a socioeconomic status-related gap in mathematical knowledge appears early and widens during early childhood. Young children from economically disadvantaged families receive less support for mathematical development both at home and in preschool. Consequently, children from different socioeconomic backgrounds enter…

This study used a randomized field trial design to evaluate the efficacy of a research-based model for scaling up an intervention focused on preschool mathematics. Although the successes of research-based educational practices have been documented, equally well known is the paucity of successful efforts to bring these practices to scale. The same…

This article presents a randomized experiment evaluating a computer-assisted tutoring program. The software program, Alphie's Alley, provides reading tutors with assessment and planning tools and performance support. It provides students with animated presentations and engaging activities. In a yearlong study involving 25 schools using the Success…