In meta-analyses of rare events, it can be challenging to obtain a reliable estimate of the pooled effect, in particular when the meta-analysis is based on a small number of studies. Recent simulation studies have shown that the beta-binomial model is a promising candidate in this situation, but have thus far only investigated its performance in a…

The purpose of this study is to determine the purpose, scope, research model, data collection tool, data analysis method and sample size of the studies on bilingualism. According to the general screening model, the documents collected were analyzed. In the first step, in order to determine the focus and scope, the objectives of the sample studies…

Peer review is valued in higher education, but also widely criticized in terms of potential biases, particularly gender. We evaluate gender differences in peer reviews of grant applications, extending Bornmann, Mutz, and Daniel's meta-analyses that reported small gender differences in favor of men (d = 0.04), but a substantial heterogeneity in…

Large sample multivariate methods for estimating and comparing effect sizes across independent samples within a single study are presented. Procedures for pooling treatment effects are provided to allow determination of overall study effect sizes for treatments with similar effects prior to implementation of meta-analyses. (TJH)

A selection model for meta-analysis is proposed that models the selection process and corrects for the consequences of selection by publication on estimates of the mean and variance of the effect parameters. Simulation studies show that the model substantially reduces bias when the model specification is correct. (SLD)