A fuzzy set-based accuracy assessment of soft classification

Despite the sizable achievements obtained, the use of soft classi®ers is still limited by the lack of well-assessed and adequate methods for evaluating the accuracy of their outputs. This paper proposes a new method that uses the fuzzy set theory to extend the applicability of the traditional error matrix method to the evaluation of soft classi®ers. It is designed to cope with those situations in which classi®cation and/or reference data are expressed in multimembership form and the grades of membership represent di€erent levels of approximation to intrinsically vague classes. Ó 1999 Elsevier Science B.V. All rights reserved.