This paper shows a proposal for Type-reduction of

an Interval Type-2 fuzzy set composed from α-cuts done over

its primary membership functions. The defi nition of available

Type-reduction methods for Interval Type-2 fuzzy sets are based

on an homogeneous subdivision of the universe of discourse, so

we propose an approximation algorithm for Type-reduction of

an Interval type-2 fuzzy set through its primary α-cuts.

Some defi nitions about the α-cut of a Type-2 fuzzy set are

provided and used for computing the centroid of an Interval

Type-2 fuzzy set through a mapping of its membership function,

instead of its universe of discourse.