The standardized mean difference (SMD) is perhaps the most important meta-analytic effect size. It is typically used to represent the difference between treatment and control population means in treatment efficacy research. It is also used to represent differences between populations with different characteristics, such as persons who are…

The Non-Cognitive Questionnaire (NCQ) is a 23-item measure assessing eight noncognitive variables that are thought to predict the performance and retention of students in college. The NCQ is widely used in research and practice. This study is a meta-analytic review of the validity of scores on the NCQ across 47 independent samples for predicting…

Basic rules are suggested to replace the signed coefficient rule to infer the form of moderator effects in terms of slopes of regression lines. Steps are provided to interpret the form of moderator effects that can be achieved using only the regression coefficients of the predictor variable and interaction term. (SLD)

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…

Effects of violating the independence assumption when combining correlation coefficients in a meta-analysis were studied. This Monte-Carlo simulation varied sample size, predictor number, population intercorrelation among predictors, and population correlation between predictors and criterion. Combining statistics from nonindependent data in a…

One of the most important effect sizes used in meta-analysis is the standardized mean difference (SMD). In this article, the conditions under which SMD effect sizes based on different measures of the same construct are directly comparable are investigated. The results show that SMD effect sizes from different measures of the same construct are…