Journal of Probability and Statistics
Volume 2011 (2011), Article ID 603856, 14 pages
Research Article

Fixed-Effects Modeling of Cohen's Weighted Kappa for Bivariate Multinomial Data: A Perspective of Generalized Inverse

1Department of Biostatistics and Epidemiology, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
2Department of Public Health Sciences, Penn State College of Medicine, 600 Centerview Drive, Suite 2200, Hershey, PA 17033-0855, USA

Received 27 August 2011; Accepted 18 October 2011

Academic Editor: Man Lai Tang

Copyright © 2011 Jingyun Yang and Vernon M. Chinchilli. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Cohen's kappa and weighted kappa statistics are the conventional methods used frequently in measuring agreement for categorical responses. In this paper, through the perspective of a generalized inverse, we propose an alternative general framework of the fixed-effects modeling of Cohen's weighted kappa, proposed by Yang and Chinchilli (2011). Properties of the proposed method are provided. Small sample performance is investigated through bootstrap simulation studies, which demonstrate good performance of the proposed method. When there are only two categories, the proposed method reduces to Cohen's kappa.