Issues in the use of kappa.

Since its introduction in 1960, the family of kappa statistics has been scrutinized for theoretical and methodological problems. A summary of recommendations made by researchers in the area is given in Table 3. Citations listing the various forms and applications of kappa are provided to assist researchers in finding the form of kappa appropriate to their needs. Readers interested in more technical treatments of any of the issues discussed herein may find the appended references helpful.