[R] Nonparametric generalization of ANOVA

[Frank E Harrell Jr]

Gabor Grothendieck wrote:
> I am happy to answer posts to r-help regardless of the name and email
> address of the poster but would draw the line at someone excessively
> posting without a reasonable effort to find the answer first or using
> it for homework since such requests could flood the list making it
> useless for everyone.

Gabor I respectfully disagree.  It is bad practice to allow anonymous 
postings.  We need to see real names and real affiliations.

r-help is starting to border on uselessness because of the age old 
problem of the same question being asked every two days, a high 
frequency of specialty questions, and answers given with the best of 
intentions in incremental or contradictory e-mail pieces (as opposed to 
a cumulative wiki or hierarchically designed discussion web forum), as 
there is no moderator for the list.  We don't need even more traffic 
from anonymous postings.

Frank

> 
> On Fri, Mar 5, 2010 at 10:55 AM, Ravi Varadhan <rvaradhan at jhmi.edu> wrote:
>> David,
>>
>> I agree with your sentiments.  I also think that it is bad posting etiquette not to sign one's genuine name and affiliation when asking for help, which "blue sky" seems to do a lot.  Bert Gunter has already raised this issue, and I completely agree with him. I would also like to urge the R-gurus to ignore such postings.
>>
>> Best,
>> Ravi.
>> ____________________________________________________________________
>>
>> Ravi Varadhan, Ph.D.
>> Assistant Professor,
>> Division of Geriatric Medicine and Gerontology
>> School of Medicine
>> Johns Hopkins University
>>
>> Ph. (410) 502-2619
>> email: rvaradhan at jhmi.edu
>>
>>
>> ----- Original Message -----
>> From: David Winsemius <dwinsemius at comcast.net>
>> Date: Friday, March 5, 2010 9:25 am
>> Subject: Re: [R] Nonparametric generalization of ANOVA
>> To: blue sky <bluesky315 at gmail.com>
>> Cc: r-help at stat.math.ethz.ch
>>
>>
>>>  On Mar 5, 2010, at 8:19 AM, blue sky wrote:
>>>
>>>  > My interpretation of the relation between 1-way ANOVA and Wilcoxon's
>>>  > test (wilcox.test() in R) is the following.
>>>  >
>>>  > 1-way ANOVA is to test if two or multiple distributions are the same,
>>>  > assuming all the distributions are normal and have equal variances.
>>>  > Wilcoxon's test is to test two distributions are the same without
>>>  > assuming what their distributions are.
>>>  >
>>>  > In this sense, I'm wondering what is the generalization of Wilcoxon's
>>>  > test to more than two distributions. And, more general, what is the
>>>  > generalization of Wilcoxon's test to multi-way ANOVA with arbitrary
>>>  > complex model formula? What are the equivalent F statistics and t
>>>  > statistics in the generalization of Wilcoxon's test?
>>>  >
>>>  > Note that I'm not interested in looking for a specific nonparametric
>>>  > test for a particular dataset right now, although this is important
>>> in
>>>  > practice. What I'm interested the general nonparametric statistical
>>>  > framework that parallels ANOVA. Could somebody give some hints on what
>>>  > references I should look for? I have google searched this topic, but
>>>  > don't find a page that exactly answered my question.
>>>
>>>  This is your first of three postings in the last hour and they are
>>> all
>>>  in a category that could well be described as requests for tutoring
>>> in
>>>  basic statistical topics. I am of the impression you have been
>>>  requested not to engage in such behavior on this list. For this
>>>  question for instance there is an entire CRAN Task View available and
>>>
>>>  you have been in particular asked to sue such resource before posting.
>>>
>>>  It's not the described role of the r-help list to remediate your lack
>>>
>>>  of statistical background, but rather to deal with difficulties in
>>>  applying the R-language to particular, discrete and exemplified
>>>  problems.
>>>
>>>  --
>>>
>>>  David Winsemius, MD
>>>  West Hartford, CT
>>>
>>>  ______________________________________________
>>>  R-help at r-project.org mailing list
>>>
>>>  PLEASE do read the posting guide
>>>  and provide commented, minimal, self-contained, reproducible code.
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
> 
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
> 


-- 
Frank E Harrell Jr   Professor and Chairman        School of Medicine
                      Department of Biostatistics   Vanderbilt University