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.…

The gold standard in making causal inference on program effects is a randomized trial. Most randomization designs in education randomize classrooms or schools rather than individual students. Such "clustered randomization" designs have one principal drawback: They tend to have limited statistical power or precision. This study aims to…

Math experts developed Formative Assessment Lessons that teachers can incorporate throughout the year's curriculum. Both tools target the "instructional core." A study by Research for Action (RFA) examining the first year of piloting the Literacy Design Collaborative (LDC) and Math Design Collaborative (MDC) tools (2010-11) found…