On 26 May 2003 09:26:39 -0500, [EMAIL PROTECTED] (Herman Rubin) wrote: > In article <[EMAIL PROTECTED]>, > john v verkuilen <[EMAIL PROTECTED]> wrote: > >Rich Ulrich <[EMAIL PROTECTED]> writes: RU > > >>A final word about assumptions: "Do the analysis both ways." > >>When you get different results, THEN you can worry about > >>what assumptions have gotten in the way.
jayv > > >This is darn good advice. IMO the main contribution of robust estimation is > >to provide systematic alternate methods, even if one intends to use standard > >ones. HR > > This is darn BAD advice. There are usually dozens of ways > of "doing the analysis", and plugging data into a cookbook > without knowing the probability assumptions is not the way > to get good answers. > Here, perhaps, is the difference between data that Herman sees, and the biostatistical applications that concern jayv and me -- Herman can say that there are "usually dozens of ways" of doing the analysis. By contrast, Jay and I have users who will be educated, and sometimes pleased and impressed at the broader picture that is provided by TWO ways of doing the analysis. By the way, If there are dozens of ways available of doing the analyses, well, the naive readers will be better served by insisting on trying all the dozens, and then improving their educations by studying and contrasting them ... than by flipping a coin to see which ONE to run. Further "by the way", It does seem to me that Herman seems to give advice as if his clients can sprout a healthy knowledge of "probability assumptions" and their consequences without ever looking at an example. By contrast, I find examples to be useful. And, if two models do NOT have different consequences that will show up in *some* computer output, then it is not worth distinguishing between them. [ snip, useful comments about robustness; symmetry] -- 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/ . =================================================================
