This figure shows the degree of bias for the SMD and UMDeffect size indexes as a function of assymetries in the underlying distributions. The results show increasing bias as the variances compared grow more assymetrical.

Figure 1Bias of SMD and UMD as a function of asymmetries in the distributions underlying the effect size estimates

SMD = standardized mean difference; UMD = unstandardized mean difference

From: Results

Cover of Meta-Analytic Statistical Inferences for Continuous Measure Outcomes as a Function of Effect Size Metric and Other Assumptions
Meta-Analytic Statistical Inferences for Continuous Measure Outcomes as a Function of Effect Size Metric and Other Assumptions [Internet].
Johnson BT, Huedo-Medina TB.

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