Principals are the second-largest school-based contributor to K-12 students' academic progress. However, there is little research evaluating whether efforts to develop principals' skills improve school effectiveness. We conducted randomized controlled trial studies of the impacts of a professional development program called the Executive…

A solid understanding of fractions is the cornerstone for acquiring proficiency with rational numbers and paves the way for learning advanced mathematical concepts, such as algebra. Fraction difficulties limit not only students' educational and vocational opportunities but also their ability to solve everyday problems. Students who exit 6th grade…

Although several studies have examined the effectiveness of reading fluency interventions, the methodological rigor of these studies remains unclear. The purpose of this study was to examine the quality of randomized controlled trial (RCT) reading fluency intervention studies using the Council for Exceptional Children (CEC) standards. Twenty-six…

To plan cluster-randomized trials with sufficient statistical power to detect intervention effects on student achievement, researchers need multilevel design parameters, including measures of between-classroom and between-school differences and the amounts of variance explained by covariates at the student, classroom, and school level. Previous…