Thanks Radford for your clear explanation. I think I am more interested in directional hypothesis, then. Would Kruskal-Wallis suffice in that case? If not, what sort of test should I be using? (I have monthly time-series county level data from 1980 - 1997). I am learning stats off of a book, but I am wasn't sure which test is appropriate for a case I described.
Thanks again, James [EMAIL PROTECTED] (Radford Neal) wrote in message news:<[EMAIL PROTECTED]>... > In article <[EMAIL PROTECTED]>, > James Choe <[EMAIL PROTECTED]> wrote: > > >I am trying to show that precipitation level in 6 selected states are > >statistically different. Is Kruskal-Wallis test appropriate for this? > >My data consists of annual average precipitation county level. > > If all you have is one number for each county (the average annual > precipitation), there is no way of doing any sort of significance > test. You would need data for many years, and would have to account > for temporal autocorrelation. > > Testing whether precipitation differs from state to state is > pointliess in any case. We KNOW that precipitation differs from place > to place, and hence from state to state. A test of a directional > hypothesis (eg, does Wyoming have more precipation than Colorado?) > would make more sense, in that at least we don't already know the > answer, but it is difficult to see why anyone would be interested. > State boundaries have no ecological significance. > > Radford Neal > > ---------------------------------------------------------------------------- > Radford M. Neal [EMAIL PROTECTED] > Dept. of Statistics and Dept. of Computer Science [EMAIL PROTECTED] > University of Toronto http://www.cs.utoronto.ca/~radford > ---------------------------------------------------------------------------- . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
