Little is known empirically about intraclass correlations (ICCs) for multisite cluster randomized trial (MSCRT) designs, particularly in science education. In this study, ICCs suitable for science achievement studies using a three-level (students in schools in districts) MSCRT design that block on district are estimated and examined. Estimates of…

In recent years, the regression discontinuity design (RDD) has gained widespread recognition as a quasi-experimental method that when used correctly, can produce internally valid estimates of causal effects of a treatment, a program or an intervention (hereafter referred to as treatment effects). In an RDD study, subjects or groups of subjects…

In this study, a web site including instructional materials such as white sheet videos, simulations, and animations and problem solving materials such as true-false questions, fill-in-the-blanks, puzzles, open-ended and multiple-choice questions regarding such important physics units as "Force" and "Movement" was designed. The purpose was to…