Measuring information and knowledge in the context of Atanassov´s intuitionistic fuzzy sets

In this paper we address the problem of how to measure information conveyed by an Atanassov´s intuitionistic fuzzy set (A-IFS for short) and a related concept of knowledge that is explicitly context oriented and useful from the point of view of a specific purpose, notably related to decision making. We pay particular attention to the relationship between the positive and negative information and a lack of information expressed by the hesitation margin.