rwg {multilevel}R Documentation

James et al., (1984) agreement index for single item measures

Description

This function calculates the within group agreement measure rwg for single item measures as described in James, Demaree & Wolf (1984). The rwg is calculated as rwg = 1-(Observed Group Variance/Expected Random Variance). James et al. (1984) recommend truncating the Observed Group Variance to the Expected Random Variance in cases where the Observed Group Variance is larger than the Expected Random Variance. This truncation results in an rwg value of 0 (no agreement) for groups with large variances.

Usage

rwg(x, grpid, ranvar=2)

Arguments

x The vector representing the construct of interest. This is the variable about which one is interested in determining whether or not group members agree.
grpid A vector identifying the groups from which x originated.
ranvar The random variance to which actual group variances are compared. The value of 2 represents the variance from a rectangular distribution in the case where there are 5 response options (e.g., Strongly Disagree, Disagree, Neither, Agree, Strongly Agree). In cases where there are not 5 response options, the rectangular distribution is estimated using the formula ranvar=(A^2-1)/12 where A is the number of response options. Note that one is not limited to the rectangular distribution; rather, one can include any appropriate random value for ranvar.

Value

grpid The group identifier
rwg The rwg estimate for the group
gsize The group size

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.

James, L.R., Demaree, R.G., & Wolf, G. (1984). Estimating within-group interrater reliability with and without response bias. Journal of Applied Psychology, 69, 85-98.

See Also

rwg.j rgr.agree rwg.j.lindell

Examples

data(lq2002)
RWGOUT<-rwg(lq2002$LEAD,lq2002$COMPID)
RWGOUT[1:10,]
summary(RWGOUT)


[Package multilevel version 2.1 Index]