A common assumption in meta-analysis is that effect sizes are independent. When correlated effect sizes are analyzed using traditional univariate techniques, this assumption is violated. This research assesses the impact of dependence arising from treatment-control studies with multiple endpoints on homogeneity measures "Q" and…

This paper examines the impact of quality-score weights in meta-analysis. A simulation examines the roles of study characteristics such as population effect size (ES) and its variance on the bias and mean square errors (MSEs) of the estimators for several patterns of relationship between quality and ES, and for specific patterns of systematic…

In this study, differential item functioning (DIF) trends were examined for English language learners (ELLs) versus non-ELL students in third and tenth grades on a large-scale reading assessment. To facilitate the analyses, a meta-analytic DIF technique was employed. The results revealed that items requiring knowledge of words and phrases in…

We examined the degree of dependence between standardized-mean-difference effect sizes in multiple-treatment studies in meta-analysis in terms of the correlation formula provided by Gleser and Olkin (1994). To explore the impact of group size and the values of the true multiple-treatment effect sizes, we simplified the formula for the correlation…

A new effect size representing the predictive power of an independent variable from a multiple regression model is presented. The index, denoted as r[subscript sp], is the semipartial correlation of the predictor with the outcome of interest. This effect size can be computed when multiple predictor variables are included in the regression model…

De Wolff and van IJzendoorn's meta-analysis supported the relation of parental behavior to attachment security; however, they concluded that sensitivity was not the best predictor of attachment security. This secondary analysis of their data re-examined their conclusion and tested moderators of the relation between sensitivity and attachment, such…

Four types of analysis are commonly applied to data from structured Rater [times] Ratee designs. These types are characterized by the unit of analysis, which is either raters or ratees, and by the design used, which is either between-units or within-unit design. The 4 types of analysis are quite different, and therefore they give rise to effect…

A new approach is presented for the meta-analysis of data from pre-test/post-test designs. With this approach, data from studies using different designs may be compared directly and studies without control groups need not be omitted. The approach is based on a "standardized mean-change" measure, computed for each sample within a study,…

The random variable p and its functions figure in several "tests of combined significance," meta-analysis summaries based on sample significance values, and ps have been used singly, as well as in other tests for evaluating the outcomes of individual research studies. In this work, asymptotic distributions of the sample one-sided…

This meta analysis examined the results of 24 studies in which traditionally certified teachers were compared with teachers with a variety of other kinds of certificates. The 24 studies allowed for the computation of 192 effect sizes, and 7 kinds of comparison were performed. Findings suggest that traditional teacher training is at least as…

Power is an indicator of the ability of a statistical analysis to detect a phenomenon that does in fact exist. The issue of power is crucial for social science research because sample size, effects, and relationships studied tend to be small and the power of a study relates directly to the size of the effect of interest and the sample size.…

Combining information to estimate standardized partial regression coefficients in a linear model is discussed. A combined estimate obtained from the pooled correlation matrix is proposed, and its large sample distribution is obtained. The method is generalized to handle a random effects model in which correlation parameters vary across studies.…

The observed probability "p" is the social scientist's primary tool for evaluating the outcome of statistical hypothesis tests. The small-sample accuracy of nonnull asymptotic distributions of several functions of "p" was studied. Implications for use of the approximations are discussed. (SLD)

This article extends both the logic and the statistical procedures used in a recent analysis of Hyde's data on gender differences in cognitive abilities by Rosenthal and Rubin. The logic of a "model fitting" approach to meta-analysis is described. Relevant statistical procedures and goodness-of-fit tests are illustrated. (Author/BS)

Differences in science achievement between males and females have been examined either directly or indirectly in a variety of studies. This investigation reviewed a quantitative synthesis of correlational research on science affect, ability, and achievement conducted by Steinkamp and Maehr. Their findings were reassessed by employing a…