Comparison of Populations Based on Attribute Data,when Covariance Matrices are Unequal

Mahalanobis—like distance indices B² and G² of BALAKRISHNAN and SANGHVI (1968) are employed to compare multinomial populations of proportions in human data. Recently, BOWERING and MISRA (1982) employed these methods, with modifications, in a different field viz. to compare fish stocks, based on meristic characters. The method of BALAKRISHNAN and SANGHVI (1968), however, assumes equality of covariance matrices, which is doubtful with multinomial populations of proportions. In this paper a statistical method for comparing such populations (where covariance matrices are not equal) is presented. Also, a feature of the G² method of BALAKRISHNAN and SANGHVI (1968) is discussed, which makes its statistical status a little more clear.