Bangdiwala's B

The test is applicable to testing the agreement between two observers. It is defined to be B = \frac{ \sum_{i=1}^k n_{ ii }^2 }{ \sum_{i=1}^k n_{ i. } n_{ .i } } where n_{ii} are the values on the main diagonal, n_{i.} is the ith row total, and n_{.i} is the ith column total of the contingency table. The value of B varies in value between 0 (no agreement) and +1 (perfect agreement). In large samples B has a normal distribution whose variance has a complicated expression. For small samples a permutation test is indicated. It may be more useful than the more commonly used Cohen's kappa in some circumstances. ==Tutorials and examples==

Worked examples of the use of Bangdiwala's B have been published. The statistical programming language R has a set of functions that will compute the B test, and a tutorial on the use of a test using these R functions is available. ==See also==