Modeling and Multivariate Methods - SAS

464 Clustering Data Chapter 18
Hierarchical Clustering
In clustering problems, it is especially useful to assign a label variable so that you can determine which
observations cluster together. In this example, country is the label variable.
When you click OK, the clustering process proceeds. The Hierarchical Cluster platform report (see
Figure 18.2) consists of a Clustering History table, a dendrogram tree diagram, and a plot of the distances
between the clusters. If you assigned a variable the label role, its values identify each observation on the
dendrogram.
Figure 18.2 Hierarchical Cluster Report
The clustering sequence is easily visualized with the help of the dendrogram, shown in Figure 18.2. A
dendrogram is a tree diagram that lists each observation, and shows which cluster it is in and when it
entered its cluster.
You can drag the small diamond-shaped handle at either the top or bottom of the dendrogram to identify a
given number of clusters. If you click on any cluster stem, all the members of the cluster highlight in the
dendrogram and in the data table.