[R] Nonparametric generalization of ANOVA

Matthew Dowle mdowle at mdowle.plus.com
Fri Mar 5 18:58:22 CET 2010

Frank, I respect your views but I agree with Gabor.  The posting guide does 
not support your views.

It is not any of our views that are important but we are following the 
posting guide.  It covers affiliation. It says only that "some" consider it 
"good manners to include a concise signature specifying affiliation". It 
does not agree that it is bad manners not to.  It is therefore going too far 
to urge R-gurus, whoever they might be, to ignore such postings on that 
basis alone.  It is up to responders (I think that is the better word which 
is the one used by the posting guide) whether they reply.  Missing 
affiliation is ok by the posting guide.  Users shouldn't be put off from 
posting because of that alone.

Sending from an anonymous email address such as "BioStudent" is also fine by 
the posting guide as far as my eyes read it. It says only that the email 
address should work. I would also answer such anonymous posts, providing 
they demonstrate they made best efforts to follow the posting guide, as 
usual for all requests for help.  Its so easy to send from a false, but 
apparently real name, why worry about that?

If you disagree with the posting guide then you could make a suggestion to 
get the posting guide changed with respect to these points.  But, currently, 
good and practice is defined by the posting guide, and I can't see that your 
view is backed up by it.  In fact it seems to me that these points were 
carefully considered, and the wording is careful on these points.

As far as I know you are wrong that there is no moderator.  There are in 
fact an uncountable number of people who are empowered to moderate i.e. all 
of us. In other words its up to the responders to moderate.  The posting 
guide is our guide.  As a last resort we can alert the list administrator 
(which I believe is the correct name for him in that role), who has powers 
to remove an email address from the list if he thinks that is appropriate, 
or act otherwise, or not at all.  It is actually up to responders (i.e. all 
of us) to ensure the posting guide is followed.

My view is that the problems started with some responders on some occasions. 
They sometimes forgot, a little bit, to encourage and remind posters to 
follow the posting guide when it was not followed. This then may have 
encouraged more posters to think it was ok not to follow the posting guide. 
That is my own personal view,  not a statistical one backed up by any 


"Frank E Harrell Jr" <f.harrell at vanderbilt.edu> wrote in message 
news:4B913880.9020701 at vanderbilt.edu...
> 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

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