On Thu, 2009-05-21 at 05:28 -0700, Pooka wrote: > Hello, > > I am a very new user to R so please have patience with me. :clap: > > I am trying to evalute the "internal response" for a couple of different > cluster methods with the help of the AdjustedRandIndex, which is included in > the mclust package. > > However, I do get a bit puzzled when I get a negative value as the value > should be in intervall of [0,1], am I correct?
0 indicates the agreement between your two raters is the same as the agreement you'd expect to get as a result of random chance. A negative value therefore indicates that the agreement between the two raters is even lower than that. G > Have I done something wrong? > Or should I interpret the negative value as the two methods do not group the > cases to the same cluster? > > I have for example used k-means and k-median, and choosen five clusters. > Each respondent has been labelled as either beloning to cluster 1,2,3,4 or > 5. I have picked out the first 32 respondents. > > Example: > > > a <- c(1,2,3,4,5,2,1,5,1,2,2,4,2,3,3,2,4,5,5,4,4,4,5,5,2,3,1,5,5,5,4,1) > b <- c(5,5,5,2,5,3,2,2,2,5,3,4,5,5,2,5,2,3,5,5,5,3,5,3,3,2,4,5,2,2,2,3) > adjustedRandIndex (a,b) > > [1] -0.01608168 > > > > Thanks in advance, > > Pooka -- %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% Dr. Gavin Simpson [t] +44 (0)20 7679 0522 ECRC, UCL Geography, [f] +44 (0)20 7679 0565 Pearson Building, [e] gavin.simpsonATNOSPAMucl.ac.uk Gower Street, London [w] http://www.ucl.ac.uk/~ucfagls/ UK. WC1E 6BT. [w] http://www.freshwaters.org.uk %~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~%~% ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.