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…

More aggregate data on school performance is available than ever before, opening up new possibilities for applied researchers interested in assessing the effectiveness of school-level interventions quickly and at a relatively low cost by implementing comparative interrupted times series (CITS) designs. We examine the extent to which effect…

Access to Head Start has been shown to improve children's preschool experiences and school readiness on selected factors through the end of 1st grade. Two more years of follow-up, through the end of 3rd grade, can now be examined to determine whether these effects continue into the middle elementary grades. The statistical design and impact…