The Problem of the Similarity of Objects in Numerical Taxonomy

The existing definitions of coefficients of association in numerical taxonomy are not sufficiently well based theoretically. The present paper aims to make more objective the definition of the coefficient of association. It proceeds from the fact that the main source of difficulty is the third value (NC) used in scoring characters, and eliminates it. An improved coefficient of association between objects is then defined as the mean value of the coefficients of association of the individual pairs of forms of objects that are constructed by the method proposed below.