The article examines the results of two quasi-experimental studies of the implementation and impact of the Literacy Design Collaborative (LDC), an intervention designed to support secondary teachers' transition to Common Core State Standards in English language arts. The first study examines LDC implementation by eighth-grade social studies and…

Randomized experiments are often considered the strongest designs to study the impact of educational interventions. Perhaps the most prevalent class of designs used in large scale education experiments is the cluster randomized design in which entire schools are assigned to treatments. In cluster randomized trials (CRTs) that assign schools to…

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.…