Hierarchical Clustering

This is a part of Cluster Analysis: we want to build a hierarchy of clusters

Two major approaches:

  • Agglomerative Clustering: This is a "bottom up" approach: each observation starts in its own cluster, and pairs of clusters are merged as one moves up the hierarchy.
  • Divisive Clustering: This is a "top down" approach: all observations start in one cluster, and splits are performed recursively as one moves down the hierarchy.