BINARY (PRESENCE-ABSENCE) SIMILARITY COEFFICIENTS

Abstract

Various numerical coefficients have been employed in comparisons of taxa or bioassociational units, especially in studies involving large arrays of multivariate data. Nomenclatural and conceptual difficulties have arisen from the translation of coefficients from variable-oriented (R-mode) to case-oriented (Q-mode) use. This paper points out the conceptual relationships and some of the properties of coefficients expressing similarity or difference between units defined by binary data.