Proactive preliminary minimum sample size determination can be useful for the early planning stages of a latent variable modeling study to set a realistic scope, long before the model and population are finalized. This study examined existing methods and proposed a new method for proactive preliminary minimum sample size determination.

This article presents 3 standardized effect size measures to use when sharing results of an analysis of mediation of treatment effects for cluster-randomized trials. The authors discuss 3 examples of mediation analysis (upper-level mediation, cross-level mediation, and cross-level mediation with a contextual effect) with demonstration of the…

This article investigates the quality of social scientific listening research that reports numerical data to substantiate claims appearing in the "International Journal of Listening" between 1987 and 2011. Of the 225 published articles, 100 included one or more studies reporting numerical data. We frame our results in terms of eight…

Three issues need to be decided in the design stage of a longitudinal intervention study: the number of persons, the number of repeated measurements per person, and the duration of the study. The degree to which polynomial effects vary across persons and the drop-out pattern also influence the statistical power to detect intervention effects. This…

Confidence intervals are widely accepted as a preferred way to present study results. They encompass significance tests and provide an estimate of the magnitude of the effect. However, comparisons of correlations still rely heavily on significance testing. The persistence of this practice is caused primarily by the lack of simple yet accurate…

Background: A literature search found five empirical studies of psychological treatment for adults with ADHD, out of 1,419 articles on ADHD in adults. Practice guidelines to date all recommend multimodal intervention, given that a significant number of patients cannot tolerate, do not respond to, or fail to reach optimal outcomes with medication…

Since meta-analysis was described in 1976 (Glass) as the application of familiar experimental methods to the integration of available research, at least five coherent approaches to meta-analysis have appeared in common use. These approaches can be divided into two broad groups. In the first group (including procedures by Robert Rosenthal, Larry…