On 18 Nov 2003 11:12:57 -0800, [EMAIL PROTECTED] (Sharon Lane-Getaz) wrote:
> > I have ordinal data that I collected by grading a statistics project based > on an established rubric. The data is being used to measure students' > increased conceptual understanding. Using the inappropriate t-tests to > measure a difference in means from year to year, the data show statistically > stignificant increases. > > However, a nonparametric approach would be more appropriate (and more > conservative.) Can someone point me in the direction of a non parametric > test that could be conducted on ordinal data? Well, gee, you could ... do a rank-order comparison? But that would probably be a stupid waste of time and energy and data. Who is going around, anyway, measuring the conceptual understanding of numerous students, using a measure that can't be scored as interval (assuming your present scores can't be regarded as interval)? I think you must be trying to start an argument - here I am - or you have been badly misled by your teachers about the robustness of the scaling of naive tests and measures. Hope this helps. -- Rich Ulrich, [EMAIL PROTECTED] http://www.pitt.edu/~wpilib/index.html "Taxes are the price we pay for civilization." . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
