Bullying among youth is recognized as a serious student problem, especially in middle school. The most common approach to measuring bullying is through student self-report surveys that ask questions about different types of bullying victimization. Although prior studies have shown that question-order effects may influence participant responses, no…

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…

This study considers the problem of testing the difference between treatment and control groups on m [greater than or equal to] 2 measures when it is assumed a priori that the treatment group will perform better than the control group on all measures. Two procedures are investigated that do not rest on the assumptions of covariance homogeneity or…

The Dunnett procedure for comparing several treatment means with a control is applied to the problem of comparing several treatment variances with the variance of a control. Appropriate critical values are specified and an example is provided. (Author)

A QuickBASIC program is described that can be used to conduct Dunnett-like comparisons on a set of independent proportions. The statistical method used, based on Levy's statistical method (1975), is an extension of the well-known Dunnett test for multiple comparisons on means. (Author/SLD)