This study was designed to assess the impact of a decision-making curriculum (PEER-DM) on the social peer relationship knowledge and self-protective decision-making skills of adolescents with disabilities in hypothetical situations involving negative peer pressure. A randomized design was used to assign students with disabilities from…

The aim of the study was to examine the effect of a 4-week classroom physical activity break intervention on middle school students' health-related physical fitness. The study was a randomized controlled trial with students assigned to the experiment and control conditions. A convenience sample comprised 94 adolescents (experiment group n = 52;…

Instructional influences on productive use of academic vocabulary were investigated among 460 mostly African American and Latina/o fifth graders from 36 classrooms in eight public schools serving low-income families. Students received a 6-week unit on wolf management involving collaborative group work (CG) or direct instruction (DI). The big…

The effects of a mathematical problem-solving intervention on students' problem-solving performance and math achievement were measured in a randomized control trial with 1,059 7th-grade students. The intervention, "Solve It!," is a research-based cognitive strategy instructional intervention that was shown to improve the problem-solving…

Interim assessments are increasingly common in U.S. schools. We use high-quality data from a large-scale school-level cluster randomized experiment to examine the impact of two well-known commercial interim assessment programs on mathematics and reading achievement in Indiana. Results indicate that the treatment effects are positive but not…

Pretest-posttest experimental designs are often used in randomized control trials (RCTs) in the education field to improve the precision of the estimated treatment effects. For logistic reasons, however, pretest data are often collected after random assignment, so that including them in the analysis could bias the posttest impact estimates. Thus,…

Three kindergartens and one prekindergarten, totaling 213 children, participated in a Behavior Modification program during the 1971-72 school year. A research assistant in each location worked directly with the teacher in measuring and evaluating teaching methods and in developing alternative procedures as needed to teach the same skills or…