PHYS THER Vol. 85, No. 3, March 2005, pp. 257-268
Julius Sim and Chris C Wright  
Primary Care Sciences Research Centre, Keele University, Keele, Staffordshire ST5 5BG, United Kingdom; School of Health and Social Sciences, Coventry University, Coventry, United Kingdom

The reliability of clinicians' ratings is an important consideration in areas such as diagnosis and the interpretation of examination findings. Often, these ratings lie on a nominal or an ordinal scale. For such data, the kappa coefficient is an appropriate measure of reliability.