title: Choosing the best index for the average score intraclass correlation coefficient.
abstract: The intraclass correlation coefficient (ICC)(2) index from a one-way random effects model is widely used to describe the reliability of mean ratings in behavioral, educational, and psychological research. Despite its apparent utility, the essential property of ICC(2) as a point estimator of the average score intraclass correlation coefficient is seldom mentioned. This article considers several potential measures and compares their performance with ICC(2). Analytical derivations and numerical examinations are presented to assess the bias and mean square error of the alternative estimators. The results suggest that more advantageous indices can be recommended over ICC(2) for their theoretical implication and computational ease.
authors.affiliation: Department of Management Science, National Chiao Tung University, Hsinchu, Taiwan, 30010, Republic of China. gwshieh@mail.nctu.edu.tw.
authors.forename: Gwowen
authors.initials: G
authors.lastname: Shieh
mesh_terms: D000465:Algorithms; D015982:Bias; D003627:Data Interpretation, Statistical; D006801:Humans; D015233:Models, Statistical; D011897:Random Allocation; D015203:Reproducibility of Results
keywords: Multilevel modeling; Random effect; Reliability