In talk.politics.drugs Szasz <[EMAIL PROTECTED]> wrote: > Erkki Komulainen <[EMAIL PROTECTED]> wrote in message >news:<atd490$5ql$[EMAIL PROTECTED]>... >> In sci.stat.edu Brian Sandle <[EMAIL PROTECTED]> wrote: >> >> : First mistake: The Pearson product-moment correlation is not a rank >> : correlation. >> >> Spearman's rank correlation IS Pearsons PMC applied to ranks (instead of >> original raw/z-scores). The above seems to stress the difference in an >> odd way. >> >> Erkki
> Thanks Erkki! You make me happy I took multivariate statistics. That > makes Sandle still zero for zero. >> _________________________________________________________________ >> <http://www.helsinki.fi.invalid/people/Erkki.Komulainen/> So I have just taken a quick look at a text used for teaching statistics in universities. That is Bruning and Kintz. It is very good with examples of calculations using many different methods, including multivariate. And it has very clear tables of how number of subjects affects the significance calculation. But if you were hurrying, and just looked at the calculation example for Pearson product moment correlation, you would not see the *assumptions* you make when using it. Yes you would see that you use it when you have actual scores attained by each subject, rather than just who is better than who. And you would see you were working with who is better than who, without knowing the scores, in Spearman's rank correlation. But here is a little question, and I am making it a little ridiculous. If you know the scores, then you also have the rank order, best to least. So you could use either test, if you know the scores. Now what Erkki said could be inferred to mean that which test you use depends on scores or not. You use the Spearman test if you do not have scores, but if you have the scores, why bother with the Pearson test, because you can use the Spearman anyway, and if you are working by hand, it is about 1/3 the work. Why? More to it? -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 80,000 Newsgroups - 16 Different Servers! =----- . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
