GmeanRel {multilevel}R Documentation

Group Mean Reliability from an lme model (nlme package)

Description

This function calculates the group-mean reliability from a linear mixed effects (lme) model. If group sizes are identical, the group-mean reliabilty estimate equals the ICC(2) estimate from an ANOVA model. When group sizes differ, however, a group-mean reliability estimate is calculated for each group based on the group size. The group-mean reliability estimate for each group is based upon the Spearman-Brown formula, the overall ICC, and group size for each group.

Usage

GmeanRel(object)

Arguments

object A Linear Mixed Effect (lme) object.

Value

ICC Intraclass Correlation Coefficient
Group A vector containing all the group names.
GrpSize A vector containing all the group sizes.
MeanRel A vector containing the group-mean reliability estimate for each group.

Author(s)

Paul Bliese paul.bliese@us.army.mil

References

Bliese, P. D. (2000). Within-group agreement, non-independence, and reliability: Implications for data aggregation and Analysis. In K. J. Klein & S. W. Kozlowski (Eds.), Multilevel Theory, Research, and Methods in Organizations (pp. 349-381). San Francisco, CA: Jossey-Bass, Inc.

Bartko, J.J. (1976). On various intraclass correlation reliability coefficients. Psychological Bulletin, 83, 762-765.

See Also

ICC1 ICC2 lme

Examples

data(bh1996)
library(nlme)
tmod<-lme(WBEING~1,random=~1|GRP,data=bh1996)
GmeanRel(tmod)

[Package multilevel version 2.3 Index]