Send to

Choose Destination
Biometrics. 1990 Jun;46(2):293-302.

Maximum likelihood estimation of agreement in the constant predictive probability model, and its relation to Cohen's kappa.

Author information

Department of Family and Community Medicine, University of Arizona, Tucson 85724.


The alpha agreement parameter is defined as the proportion of a population of items that are classified identically "for cause" by two classifiers, the remaining items being classified at random. The parameters of the corresponding constant predictive probability model are shown to be estimable by the method of maximum likelihood, and a simulation study indicates applicability of the asymptotic results to finite samples. The new estimator tends to be larger than Cohen's kappa, except in the case of uniform margins. An application is made to the validity of cancer risk items included in a cancer registry.

[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Wiley
Loading ...
Support Center