Dear Alexander, On Wed, 24 Mar 2004, Alexander Sirotkin [at Yahoo] wrote:
> Like you said, such kind of test will not give me > anything that Rand index does not, except for p-value. > > The null hypothesis, in my case, is that clustering > results does not match a different clustering, that > someone alse did on the same data. Usually, probability distributions (which you need to formulate null hypotheses) are over data, not over different methods applied to the same data. If you see two clusterings on the same data, they are identical, if they are 100% identical, and if not, then not. That's not a question of significance. What you seem to want is the assessment of stability of a clustering on given data by applying different cluster analyses, but this kind of problem is not treated in terms of "significance". Different cluster analyses do different things, and there is no reason to expect that their results are the same apart from "random variation" (the only exception is random variation in running the same algorithm such as k-means from different random starting values - but that's not a problem to investigate if you *know* the cluster analysis method that produced your clustering). Christian *********************************************************************** Christian Hennig Fachbereich Mathematik-SPST/ZMS, Universitaet Hamburg [EMAIL PROTECTED], http://www.math.uni-hamburg.de/home/hennig/ ####################################################################### ich empfehle www.boag-online.de ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
