ci.ICC2a.inter {irrICC}

Confidence Interval of ICCa(2,1), a measure of intra-rater reliability under Model 2 with interaction.

Description

This function computes the confidence interval of the Intraclass Correlation Coefficient ICCa(2,1) under the random factorial ANOVA model with subject-rater interaction. ICCa(2,1) is formulated as a measure of intra-rater reliability coefficient. This function computes the lower and upper confidence bounds of the confidence interval.

Usage

ci.ICC2a.inter(dfra, conflev = 0.95)

Arguments

dfra

This is a data frame containing 3 columns or more. The first column contains subject numbers (there could be duplicates if a subject was assigned multiple ratings) and each of the remaining columns is associated with a particular rater and contains its numeric ratings.

conflev

This is the optional confidence level associated with the confidence interval. If not specified, the default value will be 0.95, which is the most commonly-used valuee in the literature.

Value

This function returns a vector containing the lower confidence (lcb) and the upper confidence bound (ucb).

References

Gwet, K.L. (2014): Handbook of Inter-Rater Reliability - 4th ed. chapter 9, section 9.3.2, equations 9.3.7 and 9.3.8. Advanced Analytics, LLC.

Examples

#iccdata1 is a small dataset that comes with the package. Use it as follows:
library(irrICC)
iccdata1 #see what the iccdata1 dataset looks like
ci.ICC2a.inter(iccdata1)
ci.ICC2a.inter(iccdata1)$ucb #this only gives the upper confidence bound
ci.ICC2a.inter(iccdata1,0.90) #this gives you the 90% confidence interval