On 18 Feb 2002 16:29:27 -0800, [EMAIL PROTECTED] (Wuzzy) wrote: > > You should take note that R^2 is *not* a very good measure > > of 'effect size.' > > Hi Rich, you asked to see my data,
- I don't remember doing that - > i've posted the visual at the > following location http://www.accessv.com/~joemende/insulin2.gif note > that the r^2 is low despite the fact that it agrees with common sense: > Insulin levels are shown here to decrease with increasing exercise as > well as with decreasing food intake.. My r^2 is low but i think it > is clear that the above is true.. > > I've included several different views, "rating" is in MET values, i > forgot to multiply against body weight in kg to get KCAL spent per > day.. If the scattergram is meaningful, blue-ish and to the right, then the big, 3-D shaded bar-graph to the left may be thoroughly misleading. I assume that the plane imposed on both represents the regression. Do the dots in the scattergram mean something? I make sense of them; but then the bars seem to be a bad and misleading choice of plotting something-or-other. The bars are an apparent picture of something greater than R^2 of 2% -- so I am sure they don't represent *that* relationship in a proper way. My tentative conclusion is that your 2% effect really is a small one; it should be difficult to discern among likely artifacts; and therefore, it is hardly worth mentioning.... -- 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/ =================================================================
