Current practice for conducting power analyses in hierarchical trials using survey based ICC and effect size estimates may be misestimating power because ICCs are not being adjusted to account for treatment effect heterogeneity. Results presented in Table 1 show that the necessary adjustments can be quite large or quite small. Furthermore, power…

Background: There is an increased focus on randomized trials for proximal behavioral outcomes in early childhood research. However, planning sample sizes for such designs requires extant information on the size of effect, variance decomposition, and effectiveness of covariates. Objectives: The purpose of this article is to employ a recent large…

Prior research on mentoring relationships outside of school does point toward relationship closeness and related indicators of the emotional quality of the mentor-protégé tie as important influences on youth outcomes. There is preliminary evidence that this may also be the case for School Based Mentoring (SBM), or at least that closeness promotes…