ICC.CI: Confidence interval for the Intra-class Correlation

In psychometric: Applied Psychometric Theory

Confidence interval for the Intra-class Correlation

Description

Computes the CI at the desired level for the ICC1 and ICC2

Usage

ICC1.CI(dv, iv, data, level = 0.95)

ICC2.CI(dv, iv, data, level = 0.95)

Arguments

dv	The dependent variable of interest
iv	cluster or grouping variable
data	data.frame containing the data
level	Significance Level for constructing the CI, default is .95

Details

Computes the ICC from a one-way ANOVA. The CI is then computed at the desired level using formulae provided by McGraw & Wong (1996). They use the terminology ICC(1) and ICC(k) for ICC1 and ICC2 respectively.

Value

A table with 3 elements:

LCL	lower confidence limit if CI
ICC	intra-class correlation
UCL	upper confidence limit if CI

Author(s)

Thomas D. Fletcher [e-mail]

References

McGraw, K. O. & Wong, S. P. (1996). Forming some inferences about some intraclass correlation coefficients. Psychological Methods, 1, 30-46.

Bliese, P. (2000). Within-group agreement, non-independence, and reliability: Implications for data aggregation and analysis. In K. J. Klein & S. W. J. Kozlowski (Eds.), Multilevel theory, research, and methods in organizations: Foundations, extensions, and new directions (pp. 349-381). San Francisco: Jossey-Bass.

See Also

ICC.lme, ICC1, ICC2

Examples

library(multilevel)
data(bh1996)
ICC1.CI(HRS, GRP, bh1996)
ICC2.CI(HRS, GRP, bh1996)

psychometric documentation built on Nov. 6, 2023, 1:06 a.m.