On Thu, 28 Apr 2005 08:52:33 -0500 roger koenker wrote: > For my money, Frank's comment should go into fortunes. It seems a > rather Sisyphean battle to keep the lessons of robustness on the > statistical table but nevertheless well worthwhile.
Added. On more comment: maybe it's also worth noting that you don't necessarily have to rank-transform the data. Instead you can also use a permutation test based on the original observations. <advertisment> This approach is implemented in the coin package for conditional inference. </advertisment> Z > url: www.econ.uiuc.edu/~roger Roger Koenker > email [EMAIL PROTECTED] Department of > Economics vox: 217-333-4558 University > of Illinois fax: 217-244-6678 Champaign, > IL 61820 > > On Apr 28, 2005, at 7:46 AM, Frank E Harrell Jr wrote: > > > > > Usually (but not always) doing tests of normality reflect a lack of > > understanding of the power of rank tests, and an assumption of high > > power for the tests (qq plots don't always help with that because of > > their subjectivity). When possible it's good to choose a robust > > method. Also, doing pre-testing for normality can affect the type I > > error of the overall analysis. > > > > -- > > Frank E Harrell Jr Professor and Chair School of > > Medicine > > Department of Biostatistics Vanderbilt > > University > > > > ______________________________________________ > > R-help@stat.math.ethz.ch mailing list > > https://stat.ethz.ch/mailman/listinfo/r-help > > PLEASE do read the posting guide! > > http://www.R-project.org/posting-guide.html > > ______________________________________________ > R-help@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
