Search for: [Abstract = "A new ordering on the class of intuitionistic fuzzy sets, the so called π\- ordering, is introduced in this paper. As a start point we employ the modal operators on IFSs and investigate their properties in respect of the π\-ordering. In the last section the new ordering is used for the definition of the index of indeterminacy over IFSs, which is supposed to satisfy three corresponding axioms. A few versions of the index of indeterminacy are proposed according the the structure of the underlying universe X, over which the IFSs are considered. This index measures how far \(close\) is an IFS from \(to\) the family of the usual FSs on the same universe X."]