In two-level designs, the total sample is a function of both the number of Level 2 clusters and the average number of Level 1 units per cluster. Traditional multilevel power calculations rely on either the arithmetic average or the harmonic mean when estimating the average number of Level 1 units across clusters of unbalanced size. The current…

Power in multilevel models remains an area of interest to both methodologists and substantive researchers. In two-level designs, the total sample is a function of both the number of level-2 (e.g., schools) clusters and the average number of level-1 (e.g., classrooms) units per cluster. Traditional multilevel power calculations rely on either the…

Cluster randomized experiments are now widely used to examine intervention effects in prevention science. It is meaningful to use empirical benchmarks for interpreting effect size in prevention science. The effect size (i.e., the standardized mean difference, calculated by the difference of the means between the treatment and control groups,…

Although children with disabilities have been found to be at an increased risk of bullying, there are limited studies investigating predictors of bullying involvement in children with autism spectrum disorders. The current study presents findings from 1221 parents of children diagnosed with autism spectrum disorder who were selected from a…

There is growing interest in the use of a multi-tiered system of supports framework to address issues related to school climate and bullying. Positive Behavioral Interventions and Supports (PBIS) is one such model that has received considerable attention; however, nearly all of the extant literature has focused on elementary and middle schools,…

Office discipline referral (ODR) data are increasingly used to monitor student behavior problems and the impact of interventions, but there has been limited research examining their validity. The current study examined the concordance of ODRs with teacher ratings of student behavior using data on 8,645 children in 335 classrooms at 21 elementary…

Given growing concerns regarding the prevalence and seriousness of bullying, the National Education Association recently drew upon its membership to launch a national study of teachers' and education support professionals' perceptions of bullying, and need for additional training on bullying prevention efforts and school-wide policies. The data…