Different types of inexactness can be represented by fuzzy sets: vagueness, where there are no precise boundaries, ambiguity, when more than one distinguishable concept is described, generality, such that a word applies to a variety of situations, and ambivalence, where conflicting valuations can coexist. Different measures of ignorance can be used in order to grade the distinct attributes of inexact information. Here we explore some of these measures from a relational point of view.