Joe Wheaton wrote: > > I have been experimenting with different clustering solutions using the > simple matching coefficient with 13 dichotomous variables on 710 subjects. > The solution that makes the most sense uses the WAVERAGE method. I have > found a good deal about BAVERAGE (or UPGMA) but nothing about the within > group clustering method other than a statement by Aldenderfer & Blashfield > (1984, Sage) saying there are a number of variants to the average clustering > method. Can anyone give me more information?

Joe:

I am also using Within-Groups Average Linkage (WAVERAGE) in my analysis of 400 married couples. Although others who have worked with the data set I am using also used WAVERAGE, their rationale for this specific method versus others (say, Ward's) was unclear to me. The method does make intuitive sense, determining clusters based on a measure of how they hang together...

In addition to the texts that have been mentioned here, I would suggest getting hold of a SAS manual (gasp!) and reading the chapters on CLUSTER and FASTCLUS. Rather than confuse me, I found that these short sections helped me to better understand the differences between methods. They also provided a different prospective on how to go about clustering including giving some examples.

I don't know whether this is feasible for you but you might want to consider using both programs and validating what you find in one with the other. It would mean a bit more time and effort but given the current state of uncertainty concerning concensus on cluster analytical techniques, it might be a good idea.

Good luck,

Bill Allen (who is by no means an expert on CA; just another explorer...;^)