The major youth psychotherapy meta-analyses have relied on published studies, which may have led to biased effect size estimates. To examine this possibility, the authors compared 121 dissertations with 134 published studies and found the following: (a) few differences on individual methodological variables, but, overall, stronger methodology in…

Calculation of the statistical power of statistical tests is important in planning and interpreting the results of research studies, including meta-analyses. It is particularly important in moderator analyses in meta-analysis, which are often used as sensitivity analyses to rule out moderator effects but also may have low statistical power. This…

The purpose of this study was to quantitatively combine and examine the results of studies examining the effectiveness of periodized (PER) compared to nonperiodized (Non-PER) training programs for strength and/or power development. Two analyses were conducted to (a) examine the magnitude of treatment effect elicited by PER strength training…

This research evaluated the outcomes of a school psychology training practicum by replicating intervention-based service delivery procedures established in prior research. The key components include describing a service delivery model, teaching the model, deriving practice guidelines that fit the model, supporting trainees in carrying out the…

Meta-analyses of the effectiveness of college sexual assault education programs on seven outcome measure categories were conducted using 69 studies that involved 102 treatment interventions and 18,172 participants. Five of the outcome categories had significant average effect sizes (i.e., rape attitudes, rape-related attitudes, rape knowledge,…

A meta-analysis of the comparative distance education (DE) literature between 1985 and 2002 was conducted. In total, 232 studies containing 688 independent achievement, attitude, and retention outcomes were analyzed. Overall results indicated effect sizes of essentially zero on all three measures and wide variability. This suggests that many…

This article presents results from two interrelated studies. The first study conducted a meta-analysis of the published literature since 1990 to determine the magnitude of achievement problems associated with attention-deficit/hyperactivity disorder (ADHD). Effect sizes were significantly different between participants with and without ADHD…

This meta-analysis summarizes teaching effectiveness studies of the past decade and investigates the role of theory and research design in disentangling results. Compared to past analyses based on the process-product model, a framework based on cognitive models of teaching and learning proved useful in analyzing studies and accounting for…

Disclosing information, thoughts, and feelings about personal and meaningful topics (experimental disclosure) is purported to have various health and psychological consequences (e.g., J.W. Pennebaker, 1993). Although the results of 2 small meta-analyses (P. G. Frisina, J. C. Borod, & S. J. Lepore, 2004; J. M. Smyth, 1998) suggest that experimental…

This article provides a synthesis of research in which parents provided academic instruction to their own children. The effectiveness of parent tutoring in 37 studies was examined across grade level, basic skill area (e.g., reading, math), training feature (e.g., treatment length, availability of consultation), treatment fidelity, type of…

Background: Developmental dyslexia is typically defined by deficits in phonological skills, but it is also associated with anomalous performance on measures of balance. Although balance assessments are included in several screening batteries for dyslexia, the association between impairments in literacy and deficits in postural stability could be…

Meta-analysis, a way of cumulating the results of research studies, focuses on the magnitudes of effect sizes and seeks to explain effects through study characteristics. This meta-analysis used the methods developed by G. V. Glass to summarize the research on mail survey response rate manipulations. A narrative review using the same studies set…

Meta analytic procedures recommended by various authorities were the subject of a literature review designed not to discuss the relative merits of contrasting recommendations, but to find what is actually in the literature. The sample reviewed included 89 articles published between 1986 and 1992, from 2 journals and 2 information databases. Meta…

The purpose of this paper is to demonstrate how multiple linear regression provides a viable statistical methodology for dealing with meta-analysis in general, and specifically with the issues of nonindependence and design complexity, such as multiple treatments. Since the F-test and t-test are special cases of the general linear model,…

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…