In the medical research I review, the outcome variables are often rating scales. Examples would be a visual analogue scale for pain or rating scales (usually from 0 - 10) of various other factors. These data are often compared using parametric statistics. My question is.....are these scales interval/ratio or are they ordinal. My feeling is that these are ordinal data unless you can show me studies that prove the an 8 is truly twice as much as a 4. Therefore I have always used non-parametric statistics. Am I correct????
Thanks! . . ================================================================= Instructions for joining and leaving this list, remarks about the problem of INAPPROPRIATE MESSAGES, and archives are available at: . http://jse.stat.ncsu.edu/ . =================================================================
