A Computer Generated Aid for Cluster Analysis

A computer generated graphic method, which
can be used in conjunction with any hierarchical 
scheme of cluster analysis, is described and illustrated.
 The graphic principle used is the representation 
of the elements of a data matrix of similarities or dissimilarities
by computer printed symbols (of character 
overstrikes) of various shades of darkness, where a
dark symbol corresponds to a small dissimilarity. 
 The plots, applied to a data matrix before clustering
and to the rearranged matrix after clustering, 
show at a glance whether clustering brought forth any
distinctive clusters.  A well-known set of data 
consisting of the correlations of 24 psychological tests
is used to illustrate the comparison of groupings 
by four methods of factor analysis and two methods of cluster analysis.

CACM June, 1973

Ling, R. F.

computer graphics, cluster analysis, numerical
taxonomy, hierarchical clustering, factor analysis

3.10 3.30 3.36 4.49

CA730606 JB January 23, 1978  2:20 PM

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