We conducted a randomized controlled potential efficacy trial to examine effects of two variants of the Tools for Teachers (TfT) professional development (PD) intervention on preschool teachers' implementation of embedded instruction practices and children's developmental and learning outcomes. Thirty-six preschool teachers recruited from three…

Research has consistently linked early problem behavior with later adjustment problems, including antisocial behavior, learning problems and risk for the development of emotional/behavioral disorders (EBDs). Researchers have focused upon developing effective intervention programs for young children who arrive in preschool exhibiting chronic…

We investigated methods of including covariates in two-level models for cluster randomized trials to increase power to detect the treatment effect. We compared multilevel models that included either an observed cluster mean or a latent cluster mean as a covariate, as well as the effect of including Level 1 deviation scores in the model. A Monte…

Maladaptive adolescent behavior patterns often create escalating conflict with adults and peers, leading to poor long-term social trajectories. To address this, school-based behavior management often consists of contingent reinforcement for appropriate behavior, behavior reduction procedures, and placement in self-contained or alternative…

Two professional development (PD) models for teachers were compared on teacher and student outcomes. Special education teachers participated in Literacy Learning Cohorts (LLC), a PD innovation designed to improve content and pedagogical knowledge for providing reading instruction to upper elementary students with learning disabilities. The LLC,…

Estimated Type I error rates and power are reported for six tests of variance. Normal and non-normal distributions of a two-group design were investigated. Tests developed by M. B. Brown and A. B. Forsythe and by R. G. O'Brien were considered most useful. Implications are discussed. (SLD)

Results of using multimethod factor analysis and exploratory factor analysis for the analysis of three multitrait-multimethod matrices are compared. Results suggest that the two methods can give quite different impressions of discriminant validity. In the examples considered, the former procedure tends to support discrimination while the latter…

The approximate degrees of freedom Welch-James (WJ) and Brown-Forsythe (BF) procedures for testing within-subjects effects in multivariate groups by trials repeated measures designs were investigated under departures from covariance homogeneity and normality. Empirical Type I error and power rates were obtained for least-squares estimators and…