The current study describes an individual participant data meta-analysis (IPDMA) testing the efficacy of a peer-network counseling (PNC) intervention for preventing substance use escalation in adolescents and young adults. PNC has shown efficacy in reducing substance use among adolescents and young adults across small-scale randomized controlled…

Bayesian statistical approaches to mixed treatment comparisons (MTCs) are becoming more popular because of their flexibility and interpretability. Many randomized clinical trials report multiple outcomes with possible inherent correlations. Moreover, MTC data are typically sparse (although richer than standard meta-analysis, comparing only two…

This chapter introduces three applications of Bayesian inference to common and novel issues in second language research. After a review of the critiques of conventional hypothesis testing, our focus centers on ways Bayesian inference can be used for dealing with missing data, for testing theory-driven substantive hypotheses without a default null…

How parents interact with their children impacts many crucial facets of children's lives. Over the last 4 decades, researchers have identified four different parenting styles: authoritative, authoritarian, permissive, and disengaged. Hundreds of studies conducted all over the world, have identified correlations between parenting style and many…

Since heterogeneity between reliability coefficients is usually found in reliability generalization studies, moderator analyses constitute a crucial step for that meta-analytic approach. In this study, different procedures for conducting mixed-effects meta-regression analyses were compared. Specifically, four transformation methods for the…

The lack of a unified definition of giftedness leads researchers to use very different operationalizations when selecting a sample of gifted individuals for use in research. We found 104 empirical articles from 38 journals that differentiated between gifted and nongifted students which were analyzed to determine the most common methods of…

The internal/external frame of reference (I/E) model and dimensional comparison theory posit paradoxical relations between achievement (ACH) and self-concept (SC) in mathematics (M) and verbal (V) domains; ACH in each domain positively affects SC in the matching domain (e.g., MACH to MSC) but negatively in the nonmatching domain (e.g., MACH to…

This article reviews several decades of the author's meta-analytic and experimental research on the conditions under which nonrandomized experiments can approximate the results from randomized experiments (REs). Several studies make clear that we can expect accurate effect estimates from the regression discontinuity design, though its statistical…

Reliability generalization studies have provided estimates of the mean reliability coefficients and examined factors that explain the variability in the reliability estimates across studies for many different tests and measures. Different authors have used different data analyses to do such meta-analyses, and little research has addressed whether…

Social skills deficits are a central feature of autism spectrum disorders (ASD). This meta-analysis of 55 single-subject design studies examined the effectiveness of school-based social skills interventions for children and adolescents with ASD. Intervention, maintenance, and generalization effects were measured by computing the percentage of…

The Balanced Inventory of Desirable Responding (BIDR) is one of the most widely used social desirability scales. The authors conducted a reliability generalization study to examine the typical reliability coefficients of BIDR scores and explored factors that explained the variability of reliability estimates across studies. The results indicated…

Developing good criterion measures of professional performance is difficult. If criterion-related validity evidence for certification requirements could not be generalized beyond the specific context in which it was obtained, gathering that evidence would probably not be worth the effort. This paper examines two possible approaches to the…

A meta-analytic study on effectiveness of behavioral and psychotherapeutic treatments for challenging behaviors in individuals with mild mental retardation is reported. Eighty articles were examined. For each comparison, several study variables and two effect sizes (percentage of nonoverlapping data--PND and percentage of zero data--PZD) were…