A measure of agreement between m observers who rank n items in order according to some characteristic. Let Rj be the total of the ranks assigned to the jth item and let S be given by . The coefficient of concordance, W, is given by , which takes values from 0 (no general agreement) to 1 (complete agreement). The coefficient was proposed by Sir Maurice Kendall and B. B. Smith in 1939.
Subjects: Probability and Statistics.