An appropriate estimate of statistical power is critical for the design of intervention studies. Although the inclusion of a pretest covariate in the test of the primary outcome can increase statistical power, samples selected on the basis of pretest performance may demonstrate range restriction on the selection measure and other correlated…

This multiyear scale-up effectiveness study of Open Court Reading (OCR) involved approximately 4,500 students and more than 1,000 teachers per year in Grades K-5 from 49 elementary schools in seven districts across the country. Using a school-level cluster randomized trial design, we assessed the implementation and effectiveness of Open Court…

To improve the reading comprehension outcomes of children in high-poverty schools, policymakers need to identify reading interventions that show promise of effectiveness at scale. This study evaluated the effectiveness of a low-cost and large-scale summer reading intervention that provided comprehension lessons at the end of the school year and…

The present study used a randomized control trial to examine the effects of a widely used multicomponent Tier 2-type intervention, Passport to Literacy, on the reading ability of 221 fourth graders who initially scored at or below the 30th percentile in reading comprehension. Intervention was provided by research staff to groups of 4-7 students…

This study evaluated Earobics Step 1, a commercial literacy program, and examined whether impact varied with children's school readiness and classroom instruction. Participants included 247 kindergarteners from 37 classrooms in nine Title 1 schools. Children were randomly assigned to receive 21 weeks of computerized instruction with Earobics or…

This article examines the effects of one year of exposure to "Learning to Read in a Healing Classroom" (LRHC) on the reading and math skills of second- to fourth-grade children in the low-income and conflict-affected Democratic Republic of the Congo. LRHC consists of two primary components: teacher resource materials that infuse…

The purpose of the present study was to examine the effects of a program that offered sustained strategic reading instruction on reading abilities of third and fourth graders. The study was conducted among 1,469 children from 40 schools in the Netherlands. Schools were randomly assigned to either the experimental or control group. Multilevel…