Well, the discussion gets away. Perhaps I should not use 'contrasts' at all, because I took the word from the table "within subjects contrasts" although I used polynomial.
What about using effect: There was significant main effect in the within-subjects variable TASK, F(1, 4) = 3.083, p = 0.018, which is has significant in the 4th order EFFECT, F(1,1) = 5.997, p = 0.019. ? Dennis "jim clark" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > Hi > > On Mon, 26 Jan 2004, Thom wrote: > > > jim clark wrote: > > > You don't say what kind of contrasts you specified (polynomial? > > > some other?), or what pattern of differences among the means you > > > were expecting. In general, contrasts are the best way to make > > > sense of differences among multiple means, especially when there > > > are clear theoretical predictions. As for reporting the results > > > > While I agree, I would remove the "especially". Contrasts, especially > > the polynomial contrasts that SPSS prints out are not going to be useful > > in most cases unless the contrasts map onto clear (a priori) theoretical > > predictions. For example, it is pretty rare that a quartic or cubic > > contrast is readily interpretable in most contexts that I'm familiar with. > > I think Thom and I pretty much agree, although our wording and > emphasis might differ. But sometimes contrasts can be useful > even when the "theory" is weak. If one has ordered levels of a > factor (and little else to go on), for example, it is true that > the cubic or quartic or other higher-order components might > rarely be useful. Nonetheless, a substantial loading of SS > treatment on the single df linear component can enhance the > statistical significance of the effect, even turning a > non-significant omnibus effect into a significant linear effect. > I would still call this useful. > > > In this case I think the op wants to report all significant effects that > > SPSS prints out and without knowing the context ... > > Exactly right! > > Best wishes > Jim > > ============================================================================ > James M. Clark (204) 786-9757 > Department of Psychology (204) 774-4134 Fax > University of Winnipeg 4L05D > Winnipeg, Manitoba R3B 2E9 [EMAIL PROTECTED] > CANADA http://www.uwinnipeg.ca/~clark > ============================================================================ > . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
