Posted by
Dogan, Enis on
Jun 16, 2006; 5:25pm
URL: http://spssx-discussion.165.s1.nabble.com/Determining-the-number-of-clusters-tp1069116p1069117.html
SPSS 14 has a new clustering procedure: 2-steps clustering, that
determines the numb of clusters automatically. It is not very powerful
though. It usually produces two clusters (my experience) but the nice
thing about it is that it handles categorical variables as well.
To determine the best number of clusters I would also seek external
validation.
Find an external variable (that does not enter the clustering
procedure); run the clustering with 2, 3, 4, etc... number of clusters
and see if cluster membership explains the variance in this external
variable. The external variable should, of course, be related to the
clusters to begin with.
Hope this helps
You might also want to consider Latent Class analysis for this
purpose...
Enis
-----Original Message-----
From: SPSSX(r) Discussion [mailto:
[hidden email]] On Behalf Of
Christian Bautista
Sent: Friday, June 16, 2006 10:55 AM
To:
[hidden email]
Subject: Determining the number of clusters
I'm applying a hierarchical cluster analysis in order to determine
groups
of cases. As you know SPSS give us a range of potential number of
clusters.
However, is there any methodology or specific procedure to follow to
define
what is the most correct number of clusters?
Thanks,
/Christian