  Irreducible interval exchange transformations are studied with regard to
whirly property, a condition for non-trivial spatial factor. Uniformly whirly
transformation is defined and to be further studied. An equivalent condition is
introduced for whirly transformation. We will prove that almost all 3-interval
exchange transformations are whirly, using a combinatorics approach with
application of the Rauzy-Veech Induction. It is still an open question whether
whirly property is a generic property for m-interval exchange transformations
(m>=4).
