How to measure the amount of knowledge conveyed by Atanassov’s intuitionistic fuzzy sets

We address the problem of how to measure the amount of knowledge conveyed by the Atanassov’s intuitionistic fuzzy set (A-IFS for short). The problem is relevant from the point of view of many application areas, notably decision making. An amount of knowledge considered is strongly linked to its related amount of information. Our analysis is concerned with an intrinsic relationship between the positive and negative information and a lack of information expressed by the hesitation margin. Illustrative examples are shown.