Do We Overestimate the Within-Variability? The Impact of Measurement Error on Intraclass Coefficient Estimation.

ABSTRACT: Many psychological phenomena have a multilevel structure (e.g., individuals within teams or events within individuals). In these cases, the proportion of between-variance to total-variance (i.e., the sum between-variance and within-variance) is of special importance and usually estimated by the intraclass coefficient (1) [ICC(1)]. Our contribution firstly shows via mathematical proof that measurement error increases the within-variance, which in turn decreases the ICC(1). Further, we provide a numerical example, and examine the RMSEs, alpha error rates and the inclusion of zero in the confidence intervals for ICC(1) estimation with and without measurement error. Secondly, we propose two corrections [i.e., the reliability-adjusted ICC(1) and the measurement model-based ICC(1)] that yield co

SUBMITTER: Wilms R 

PROVIDER: S-EPMC7248308 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature