Chapter in Views on Fuzzy Sets and Systems from Different Perspectives, edited Rudolf Seising, in “Studies in Fuzziness and Soft Computing”, series editor Janusz Kacprzyk.

Type-2 fuzzy sets offer the opportunity to capture higher orders of uncertainty. However, researchers have not explored fully the nature of this uncertainty and how it can be quantified. In this paper we place type-2 fuzzy sets in the context of logic and model them, for the first time, as a collection of meta statements. The paper provides a full discussion on this new perspective. We also propose new approaches to measuring the uncertainty represented by a type-2 fuzzy set