
CHAPTER 4
Clustering Analysis
4.1 Clustering Analysis
Clustering analysis is an important learning method which doesn’t need any
prior knowledge. Clustering is usually performed when no information is
available concerning the membership of data items to predefi ned classes. For
this reason, clustering is traditionally seen as part of unsupervised learning.
We nevertheless speak here of unsupervised clustering to distinguish it from
a more recent and less common approach that makes use of a small amount
of supervision to “guide” or “adjust” clustering. In this chapter, we focus
on discussing this unsupervised learning method. The aim of clustering ...