mokken (version 3.0.4)

ICC: Intraclass correlation

Description

Computes to intraclass correlation for multilevel data (ICC; Snijders & Bosker, 1999, p. 17) for each item and the total scale of a questionnaire (Koopman, Van der Ark, & Zijlstra, 2020) and the F-test for the null hypothesis that the (total scale) ICC is zero (Snijders & Bosker, 2012, p. 22)

Usage

ICC(X)

Arguments

X

matrix or data frame of numeric data containing a grouping column and the item scores of nrow(X) respondents to ncol(X) - 1 items. Missing values are not allowed

Value

itemICC

The ICC per item

scaleICC

The ICC for the total scale and the corresponding results for the F-test

References

Koopman, L. Zijlstra, B. J. H, & Van der Ark, L. A. (2020). A two-step procedure for scaling multilevel data using Mokken's scalability coefficients. Manuscript submitted for publication.

Snijders, T. A. B., & Bosker, R. J. (2012). Multilevel analysis: An introduction to basic and advanced multilevel modeling (2nd ed.). Sage.

See Also

SWMDK, MLcoefH,

Examples

# NOT RUN {
# Data example (Koopman et al., 2020)
data(SWMDK)

# Compute ICC
ICC(SWMDK)

# }