The power of statistical tests in meta-analysis.
Calculations of the power of statistical tests are important in planning research studies (including meta-analyses) and in interpreting situations in which a result has not proven to be statistically significant. The authors describe procedures to compute statistical power of fixed- and random-effects tests of the mean effect size, tests for heterogeneity (or variation) of effect size parameters across studies, and tests for contrasts among effect sizes of different studies. Examples are given using 2 published meta-analyses. The examples illustrate that statistical power is not always high in meta-analysis.
Hedges
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LV
Department of Education, University of Chicago, 5835 South Kimbark Avenue, Chicago, Illinois 60637, USA. hedge@src.uchicago.edu
Pigott
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TD
D006801:Humans; D015201:Meta-Analysis as Topic; D008960:Models, Psychological