On Wed, 13 Aug 2003 10:13:47 +0200, Torsten Franz <[EMAIL PROTECTED]> wrote:
> > Do you expect the same result for different input? ! > Definitely not, although the underlying data set is the same. My > question was: why are the results different? Because the matrices are > different? Is the answer so simple? And which conclusions I have to draw > for the interpretation of the MDS? > I tried to do MDS on correlations, 15 years ago when I was trying to figure out if MDS was worth anything, and I never figured out how I was supposed to reverse the correlations in order to have a 'distance' metric that would work. Did you have some concrete advice from somewhere? Since the results I could get on correlations did not look nearly as meaningful to me as what Factor Analysis gave me, I decided to forget about MDS. I googled for < "Multidimensional scaling" FAQ > and two of the first 4 hits were to my own FAQ -- that is not encouraging. < "Multidimensional scaling" tutorial > gave a better looking set of references. Has somebody cared enough about MDS to update the computer programs? It's long been my impression that 'marketing' was using MDS. From google, it also seems like MDS sometimes is included in the tools of data mining. -- Rich Ulrich, [EMAIL PROTECTED] http://www.pitt.edu/~wpilib/index.html "Taxes are the price we pay for civilization." Justice Holmes. . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
