Hierarchical clustering

• Single linkage
• Complete linkage
• Average linkage
• Ward’s linkage (including Ward’s method)
• Weighted-average linkage
• Centroid linkage
• Median linkage

Nonhierarchical

• Kmeans
• Kmedians

Cluster on observations

Cluster using any dissimilarity matrix

Dendrograms

• Full trees
• Subtrees
• Upper portion of tree
• Vertical or horizontal orientation
• Branch counts

Stopping rules

• Calínski and Harabasz pseudo-F index
• Duda and Hart Je(2)/Je(1) index

Support tools

• Generate summary and grouping variables
• Attach notes to analyses

Similarity/dissimilarity measures for continuous data

• L2/Euclidean
• L1/absolute/cityblock/manhattan
• L(#)
• Canberra
• Correlation
• Angular