Two estimators of effect size that are based on the sample quartiles are proposed and studied. One is for the situation where a treatment effect is evaluated against a control group, and the other is for a situation in which two parallel treatments are compared. Both are illustrated and evaluated. (SLD)

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)

Subjected 81 research studies on Ivey's (1971) microcounseling program to a comprehensive meta-analysis, assessing the relation between effect size and the sampling distribution of several important methodological and substantive characteristics. Results suggest that the microcounseling program is educationally effective for teaching simple,…

Discusses the cost effectiveness of training interventions for industry and education. Highlights include the differences between cost-benefit analysis and cost-effectiveness analysis; measuring effects; the development of meta-analysis; cost and its measurement; cost-effectiveness ratios; and an example of the cost-effectiveness of computer-based…

Compares results of Hunter-Schmidt meta-analytic technique with results of Glass meta-analytic technique on three meta-analytic data sets chosen from the literature, hypothesizing that the Hunter-Schmidt mean effect size would be significantly larger than the Glass mean effect size because of correlation for measurement error. Results confirmed…

Two new methods of estimating the mean population correlation (M) and the standard deviation of population correlations (SD) were suggested and tested by Monte Carlo simulations. Results show no consistent advantage to using the Pearson correlation or Fisher's Z in estimating M or SD; estimates from all methods are similar. (SLD)

Explores the nature of meta-analysis by placing it in the context of research synthesis. Methods of meta-analysis are described and compared with other forms of research integration, and findings for several meta-analyses are provided to show advantages of quantitative review methods. (SLD)

Some guidelines are offered for interpreting and evaluating meta-analytic reviews of research. The choice of unit of analysis, the issue of fixed versus random effects, the meaning of heterogeneity, the determination of appropriate contrasts, and the choice of measures of central tendency are discussed. (SLD)

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)

In contrast to the average effect sizes of the approach to metanalysis that can be thought of as literature synthesis, an effect-size surface is proposed as a function of scientifically relevant factors, estimated by extrapolating a response surface of observed effect sizes to a region of ideal studies. (SLD)

Kendall's Tau is often considered equivalent to Spearman's Rho as an ordinal measure of correlation in spite of its different metric. Formulas for converting Tau to Rho are reviewed; and a table of corresponding values is presented for Tau, Rho, and several related indices. (SLD)

Discusses computer simulation and analyzes evidence concerning the effectiveness of simulation by examining the relationship between two forms of simulations, pure and hybrid; and two modes of instruction, presentation and practice. Presents results of a meta-analysis of 19 studies on simulation effects, including effect size for academic…

Discusses how meta-analysis allows clinicians to determine objectively both presence and size of an effect or correlation within the existing literature by pooling the results of various studies and performing statistical analyses. Describes the risks and benefits of applying information obtained from meta-analysis into clinical practice.…

Eighty-three studies from 1982 to 2001 with formal training interventions were integrated via meta-analytic techniques to determine the effectiveness of interventions in their enhancement of performance, knowledge, and expertise at the individual, team or group, or organizational level. The studies were separated by research design, with the…

Because of the requirement of reporting effect sizes and in the interest of measurement of change within the item response theory framework, their combination becomes a new issue. In the present study, repeated measures are decomposed as an initial ability and one or more modifiabilities (gain score) using a multidimensional Rasch model. The…