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ERIC Number: ED562265
Record Type: Non-Journal
Publication Date: 2015
Reference Count: 8
Small-Sample Adjustments for Tests of Moderators and Model Fit in Robust Variance Estimation in Meta-Regression
Tipton, Elizabeth; Pustejovsky, James E.
Society for Research on Educational Effectiveness
Randomized experiments are commonly used to evaluate the effectiveness of educational interventions. The goal of the present investigation is to develop small-sample corrections for multiple contrast hypothesis tests (i.e., F-tests) such as the omnibus test of meta-regression fit or a test for equality of three or more levels of a categorical moderator. Drawing on work that addresses related, simpler problems and special cases of cluster-robust variance estimation, the authors develop three small-sample tests based on different approximations to the distribution of a robust Wald test statistic. In the remainder of the study, the authors describe their modeling assumptions, proposed tests, and some initial simulation result. These approximations are drawn from a wide array of areas within statistics, ranging from econometrics to survey sampling. The paper presents both new analytic work describing these small-sample corrected test statistics and the results of a large simulation study that compares these potential solutions, as well as a discussion of the implications of our findings for practice. Tables and figures are appended.
Descriptors: Randomized Controlled Trials, Sample Size, Effect Size, Hypothesis Testing, Regression (Statistics), Robustness (Statistics), Mathematical Models, Simulation, Statistical Bias, Sampling, Economics, Hierarchical Linear Modeling, Meta Analysis
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Publication Type: Reports - Research
Education Level: N/A
Authoring Institution: Society for Research on Educational Effectiveness (SREE)