Background: Cluster-randomized experiments that assign intact groups such as schools or school districts to treatment conditions are increasingly common in educational research. Such experiments are inherently multilevel designs whose sensitivity (statistical power and precision of estimates) depends on the variance decomposition across levels.…

Math Snacks animations and support materials were developed for use on the web and mobile technologies to teach ratio, proportion, scale factor, and number line concepts using a multi-modal approach. Included in Math Snacks are: Animations which promote the visualization of a concept image; written lessons which provide cognitive complexity for…

This brief describes a quasi-experimental study of Word Generation, conducted in public middle schools in Boston. Word Generation is a robust vocabulary intervention that is implemented across key subject areas. The purpose of the program is to enhance students' vocabulary in support of improved reading comprehension. The brief outlines the…