Generalizability Theory Applied to Categorical Data

The main purposes of the present article are (a) to exemplify a link between Fleiss's multiple-rater kappa or other analogues and the generalizability (G) coefficient for a single facet design, (b) to explore the possible utility and interpretation of G theory in the study of interrater agreement when the data are measured on a nominal scale, and (c) to explain why the G coefficient is preferred in place of the kappa coefficient and its derived forms.