“…The standard K-means algorithm has also been used with some success [Ding et al, 1994;Toft et al, 1997;Goutte et al, 1999], as have hierarchical approaches to clustering [Goutte et al, 1999;Filzmoser et al, 1999]. Also, using hierarchical arguments together with a nonparametric approach, innovative methods are starting to appear [e.g., Wismü ller et al, 1998;Domany, 1999;Goutte, unpublished research].…”