3.1 Overview
Hierarchical methods (except Ward’s method, median and centroid method; see next
chapter) require the specification of a dissimilarity or similarity measure. In general, four
groups of dissimilarity resp. similarity measures can be distinguished:
1. Correlation coefficients, also labelled association measures.
2. Distance measures.
3. Derived measures. They are derived from correlation coefficients or from distances.
4. Other dissimilarity or similarity measures. They have been developed for special
purposes, mainly for binary variables.