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Luca,
You mean weighting VARIABLES, not CASES (the latter being the more usual
application of weighting). When applying clustering procedures, the unit of
measurement of variables is irrelevant (all are standardized internally to a
zero mean and unit standard deviation), so that, say, multiplying your two
priority variables by some factor would have no effect.
One possibility is forgetting about clustering altogether, and run a factor
analysis on the seven variables. The risk is that FA may not give higher
weight to the two "chosen" variables but to some other ones. Data are
stubborn sometimes.
Another possibility is classifying the cases only by those two priority
variables, into a small number of classes (this can be done by cluster
analysis or some other procedure), and then refining the classification by
means of the other 5. I guess the number of groups may thus grow very large,
though.
At the moment I do not have more precise ideas about this. Perhaps others
may come up with something better.
Hector
-----Mensaje original-----
De: SPSSX(r) Discussion [mailto:SPSSX-L@LISTSERV.UGA.EDU] En nombre de Luca
Meyer
Enviado el: Friday, February 10, 2006 10:57 AM
Para: SPSSX-L@LISTSERV.UGA.EDU
Asunto: Weighted cluster analysis
Hello,
I have been asked to run cluster analysis on a database to identify
omogeneous groups of cases. I have also been asked to weight a couple of
variable more than the other 7 so that groups will depend more heavily on
variability on these 2 variables. What would be my best choice for
procedures? Should I look into AnswerTree?
Thanks,
Luca
PS: I only have a license for SPSS Base and Ctables, I do not have other
SPSS products
Mr. Luca MEYER
Survey research, data analysis & more: http://lucameyer.blogspot.com/
Tel: +390122854456 - Fax: +391782232575 - Mobile: + 393394950021
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