Using a Weighted Kap with an Unused Rating
Sometimes, for whatever reason, a rater does not use a category. For example, once more using the data from the two rater example, pretend that no person was rated neutral by either party. Thus the data would look like this (click to download) and the command kap raterA raterB, wgt(w) would be calculated with a three item matrix, as follows.
Luckily, Stata anticipated this case and included the absolute option. Thus, to calculate the agreement matrix with all four actual possible values, the command becomes kap raterA raterB, absolute wgt(w) and the output now displays awareness of four possible rating categories.
