### Table 2Standardized mean difference (SMD) ES estimations (and their components) for two independent groups

No.SourceEquationComponents
6.Hedges (1981)25 $dhb=c(N-2)Y¯PostE-Y¯PostCSPooled$ $c(N-2)=1-34(N-2)-1SPooled=(nE-1)SE2+(nC-1)SC2nE+nC-2$
N = nE + nC
SE = post-test standard deviation of the experimental group
SC = post-test standard deviation of the control group
$Y¯PostE$= post-test mean of the experimental group
$Y¯PostC$= post-test mean of the control group
7.Becker (1988)19 $db=c(N-2)[Y¯PostE-Y¯PreESPreE-Y¯PostC-Y¯PreCSPreC]$
8.Gibbons et al. (1993)23 $dg=c(N-2)[Y¯DiffESDiffE-Y¯DiffCSDiffC]$
9.Huedo-Medina and Johnson (2011)24 $dhw=c(N-2)[Y¯PostE-Y¯PreESwithin-poolE-Y¯PostC-Y¯PreCSwithin-poolC]$
10.Shadish et al. (1999)26 $ds1=Y¯PostE-Y¯PostCSPooled$ $SPooled=(nE-1)SE2+(nC-1)SC2nE+nC-2SE=∣Y¯PreE-Y¯PostE∣nl∣tdE∣2(1-rPre,PostE)SC=∣Y¯PreC-Y¯PostC∣nl∣tdC∣2(1-rPre,PostC)$
11.Shadish et al. (1999)26 $ds2=Y¯PostE-Y¯PostCSANOVA$ $SANOVA=MSEb+(tp-1)MSEwtp$
MSEb = between-subjects mean square error
MSEw = within-subjects mean square error
tp = number of measured time points
12.Shadish et al. (1999)26 $ds3=Y¯PostE-Y¯PostCSANCOVA$ $SANCOVA=MSEa(N-h-1)(1-rw-class2)(N-h)rw-class=FcovFcov+(N-h-1)$
MSEa = adjusted mean square error from the covariance analysis

From: Introduction

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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