Some issues in robust clustering
Christian Hennig
Some key issues in robust clustering are discussed with focus on Gaussian
mixture model based clustering, namely the formal definition of outliers,
ambiguity between groups of outliers and clusters, the interaction between
robust clustering and the estimation of the number of clusters, the essential
dependence of (not only) robust clustering on tuning decisions, and
shortcomings of existing measurements of cluster stability when it comes to
outliers.