Multilevel modeling (MLM) is frequently used to detect cluster-level group differences in cluster randomized trial and observational studies. Group differences on the outcomes (posttest scores) are detected by controlling for the covariate (pretest scores) as a proxy variable for unobserved factors that predict future attributes. The pretest and…

Starting Strong in Kindergarten (Starting Strong) is a school-based indicated prevention targeting behavior problems, student-teacher relationships, and parent-school connectedness for children with or at risk for disruptive behavior problems during the transition to kindergarten. By use of a block-randomized, controlled trial to test program…