I. Purpose of the Study: Detecting whether interventions work or not (through main effect analysis) can provide empirical evidence regarding the causal linkage between malleable factors (e.g., interventions) and learner outcomes. In complement, moderation analyses help delineate for whom and under what conditions intervention effects are most…

Sample size determination in multilevel randomized trials (MRTs) and multilevel regression discontinuity designs (MRDDs) can be complicated due to multilevel structure, monetary restrictions, differing marginal costs per treatment and control units, and range restrictions in sample size at one or more levels. These issues have sparked a set of…

Initiatives during the Bush Administration and the Obama Administration may have set the stage for a"Golden Age of evidence-based policy" (Haskins, 2015). Together these efforts stress the importance of accurate, internally valid evidence that can inform decisions to more efficiently allocate public resources. In 2002, the U.S.…