atten {MAd}

Correction for Attenuation

Description

Used to correct for attenuated effect sizes due to measurement unreliability.

Usage

atten(g, xx, yy, data)

Arguments

g

Hedges g (unbiased estimate of d) effect size.

xx

Column for reliability of predictor variable ("independent variable").

yy

Column for reliability of outcome variable ("dependent variable").

data

data.frame with the above values.

Value

A new column for g corrected for attenuation (g.corrected) will be added to the data, for those xx & yy columns with complete data.

Author(s)

AC Del Re & William T. Hoyt

Maintainer: AC Del Re [e-mail]

References

Hunter, J. E., Schmidt, F. L. (2004). Methods of meta-analysis (2nd edition). Thousand Oaks, CA: Sage.

Examples

# Sample data:

id<-c(1, 1:19)
n<-c(10,20,13,22,28,12,12,36,19,12,36,75,33,121,37,14,40,16,14,20)
g<-c(.68,.56,.23,.64,.49,-.04,.49,.33,.58,.18,-.11,.27,.26,.40,.49,
 .51,.40,.34,.42,.16)
var.g <- c(.08,.06,.03,.04,.09,.04,.009,.033,.0058,.018,.011,.027,.026,.0040,
  .049,.0051,.040,.034,.0042,.016)
xx<-c(.88,.86,.83,.64,.89,.84,.89,.83,.99,.88,.81,.77,.86,.70,.79,
 .71,.80,.74,.82,.86)  # Reliability of "independent variable"
yy<-c(.99,.86,.83,.94,.89,.94,.89,.93,.99,.88,.81,.77,.86,.70,.79,
 .71,.80,.94,.92,.96)  # Reliability of "dependent variable"
   
df<-data.frame(id,n,g, var.g, xx,yy)

# Example        
atten(g= g, xx = xx, yy = yy, data= df)