On 18 Apr 2002 14:09:05 -0700, [EMAIL PROTECTED] (Voltolini) wrote: > Dear friends, I would like to know how to discuss the Gamma correlation > results ! > > For example, I am using the software STATISTICA and I have a result like: > Gamma=0,37; Z=5,47; p=0,00. > > But.... what is the meaning of 0,37 ??? > > I found in some books that this is a probability and not a simple > correlation index like Pearson or Spearman correlation.
Do you mean, not one of the books gives you the formula? So you wonder what it is that the "probability" measures? - I believe that gamma is included in the SPSS output; and some documentation will be on the SPSS web site (crosstabs). The old paper documentation says, P-Q over P+Q, where P and Q have these really awkward and confusing definitions (under the write-up for Kendall's tau) as the number of "concordant" and "discordant" pairs of ranks. If ties are not possible, then P over P+Q would be the fraction "concordant". P-Q seems to stretch or adapt that scaling to the correlation-type range of minus 1 to plus 1. A: I could ask: Do you really want to use a stat-pack that doesn't document what they are giving you? B: On the other hand, if you want a discussion to relay to your students, instead of a formula, I haven't given you much to work with, either. -- Rich Ulrich, [EMAIL PROTECTED] http://www.pitt.edu/~wpilib/index.html . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
