DESCRIPTION OF any procedure is often most effectively accomplished by comparison to another procedure. To clarify an understanding of hierarchical cluster analysis, we will compare it to factor analysis. Cluster analysis is in some ways similar to factor analysis (Chapter 20), but it also differs in several important ways. If you are unfamiliar with factor analysis, please read through the introduction of Chapter 20 before attempting this chapter. The introductory paragraphs of this section will compare and contrast cluster analysis with factor analysis. Following this, the sequential steps of the cluster analysis procedure will be identified, along with a description of the data set used as an example to aid in the understanding of each step of the process.