multilevel (version 2.7)

gmeanrel: Group Mean Reliability from an lme model (nlme package)

Description

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 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.

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

# NOT RUN {
data(bh1996)
library(nlme)
tmod<-lme(WBEING~1,random=~1|GRP,data=bh1996)
gmeanrel(tmod)
# }