Editorial note: referees |
| |
| Authors: | Mariola Moeyaert Maaike Ugille S. Natasha Beretvas John Ferron Rommel Bunuan Wim Van den Noortgate |
| |
| Affiliation: | 1. Department of Educational Psychology and Counseling, State University of New York at Albany, Albany, New York, USAmmoeyaert@albany.edu;3. Department of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium;4. Department of Educational Psychology, University of Texas at Austin, Austin, Texas, USA;5. Educational Measurement and Research, University of South Florida, Tampa, Florida, USA |
| |
| Abstract: | AbstractThis study investigates three methods to handle dependency among effect size estimates in meta-analysis arising from studies reporting multiple outcome measures taken on the same sample. The three-level approach is compared with the method of robust variance estimation, and with averaging effects within studies. A simulation study is performed, and the fixed and random effect estimates of the three methods are compared with each other. Both the robust variance estimation and three-level approach result in unbiased estimates of the fixed effects, corresponding standard errors and variances. Averaging effect sizes results in overestimated standard errors when the effect sizes within studies are truly independent. Although the robust variance and three-level approach are more complicated to use, they have the advantage that they do not require an estimate of the correlation between outcomes, and they still result in unbiased parameter estimates. |
| |
| Keywords: | Meta-analysis dependent effect sizes robust variance estimation multilevel meta-analysis averaging effects |
|
|
