The dendrogram is a graphical representation of the results of hierarchical cluster analysis . This is a tree-like plot where each step of hierarchical clustering is represented as a fusion of two branches of the tree into a single one. The branches represent clusters obtained on each step of hierarchical clustering.

An example of the dendrogram (produced by XLMiner software) is shown below.

(For more detailed description of the dendrogram, see this chapter of the XLMiner online help.)

See also the short online courses

Cluster Analysis ,

Data Mining: Unsupervised Techniques .