Using k-Specificity for the Management of Count Restrictions in Flexible Querying.

In the field of Fuzzy Set Theory, special attention has been paid to the problem of determining whether a fuzzy set is a singleton, by means of the well-known measures of specificity. This has been done, for example, to be able to measure the level of uncertainty associated with the fuzzy set or, also, to be able to determine the discriminatory power of the property associated with the fuzzy set in a given context. This concept was extended to that of k-specificity in order to determine the difficulty of choosing k objects in a fuzzy set. In this paper we study bounding properties for k-specificity measures, and we introduce their use in flexible querying, analyzing their computation, and comparing the information provided by these measures with the tightly related fuzzy cardinality measures.