On Sun, 28 Jan 2001 13:57:02 -0500, "K. Bloom" <[EMAIL PROTECTED]> wrote: > I just ran some data through a simple one way polynomial analysis in spss. > I had 3 groups and very unequal n's. By hand, I calculated the contrast > estimates for both the linear and quadratic trends using the unweighted > formula for determining coefficients. The value I got was different than the > value of contrast estimates I got from the spss printout. So I tried to > compute new coefficients weighted for sample sizes. But when I did that I > got bizarre linear and quadratic contrast estimates. Help. > > Here are my data for the three groups... < snip, detail of problem, possible solutions ...> > perhaps someone knows that formula that spss uses to calculate the > polynomial contrast estimates. > I've had trouble navigating the SPSS site, so I finally bookmarked the algorithms. SPSS documents this one at - http://www.spss.com/tech/stat/algorithms/oneway.pdf It appears that "group" codes are used as codes for spacing. -- Rich Ulrich, [EMAIL PROTECTED] http://www.pitt.edu/~wpilib/index.html ================================================================= Instructions for joining and leaving this list and remarks about the problem of INAPPROPRIATE MESSAGES are available at http://jse.stat.ncsu.edu/ =================================================================
