[R] Nonparametric generalization of ANOVA

(Ted Harding) Ted.Harding at manchester.ac.uk
Fri Mar 5 20:37:40 CET 2010

Again, I have the same attitude as Gabor. I don't need to know the
real identity of a poster, if they ask a sensible question (which
may well be elementary).

As a contribution to the discussion, may I point out that many people
use different email addresses for different purposes, so that any
traffic involving a particular email address gets dropped into a
particular folder. If you are running a private server you can pick
whatever you like. If, like Blue Sky, you are on gmail, you will
need to pick an identity that is not already taken. So perhaps
Blue Sky (wheoever he/she is) may be using bluesky315 at gmail.com
to encapsulate their R-help correspondence.

Or perhaps not; but other people do (e.g. jluo.rhelp at gmail.com,
amitrhelp at yahoo.co.uk, rhelpacc at gmail.com -- for the first two
we do have a name though no affiliation; for the latter, neither
name nor affiliation). It doesn't matter much, in my view.

Some of the opinions expressed seem to kinterpret this kind of
"anonymity" as a smoke-screen for students who are trying to get
their homework done, to hide from their teachers. This no doubt
happens, but that should not justify a knee-jerk assumption that
it is the case.

And I do find it a bit distasteful to see people being beaten about
the head with the posting guide on slight pretexts. I hope we can
be more relaxed.


On 05-Mar-10 18:47:31, Matthew Dowle wrote:
> John,
> So you want BlueSky to change their name to "Paul Smith" at
> "New York  University", just to give a totally random, false
> name, example,  and then you will be happy ?  I just picked a
> popular, real name at a real, big place. Are you, or is anyone
> else,  going to check its real ?
> We want BlueSky to ask great questions,  which haven't been
> asked before, and to follow the posting guide.  If BlueSky
> improves the knowledge base whats the problem?  This person
> may well be breaking the posting guide for many other reasons
> (I haven't looked), and if they are then you could take issue
> with them on those points, but not for simply writing as
> "BlueSky".
> David W has got it right when he replied to "ManInMoon". Shall
> we stop this thread now, and follow his lead? I would have
> picked "ManOnMoon" myself but maybe that one was taken. Its
> rather difficult to be on a moon, let alone inside it.
> Matthew
> "John Sorkin" <jsorkin at grecc.umaryland.edu> wrote in message 
> news:4B910687020000CB00064244 at medicine.umaryland.edu...
>> The sad part of this interchanges is that Blue Sky does not seem to be
>> amiable to suggestion. He, or she, has not taken note, or responded to
>> the 
>> fact that a number of people believe it is good manners to give a real
>> name and affiliation. My mother taught me that when two people tell
>> you 
>> that you are drunk you should lie down until the inebriation goes
>> away. 
>> Blue Sky, several people have noted that you would do well to give us
>> your 
>> name and affiliation. Is this too much to ask given that people are
>> good 
>> enough to help you?
>> John
>> John David Sorkin M.D., Ph.D.
>> Chief, Biostatistics and Informatics
>> University of Maryland School of Medicine Division of Gerontology
>> Baltimore VA Medical Center
>> 10 North Greene Street
>> GRECC (BT/18/GR)
>> Baltimore, MD 21201-1524
>> (Phone) 410-605-7119
>> (Fax) 410-605-7913 (Please call phone number above prior to faxing)>>>
>> "Matthew Dowle" <mdowle at mdowle.plus.com> 3/5/2010 12:58 PM >>>
>> 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
>> evidence.
>> Matthew
>> "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
>> ______________________________________________
>> 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.
>> Confidentiality Statement:
>> This email message, including any attachments, is for ...{{dropped:5}}
> ______________________________________________
> 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.

E-Mail: (Ted Harding) <Ted.Harding at manchester.ac.uk>
Fax-to-email: +44 (0)870 094 0861
Date: 05-Mar-10                                       Time: 19:37:34
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