[R] correlation coefficient

[Jim Lemon]

Dieter Menne wrote:
> Bert Gunter <gunter.berton <at> gene.com> writes:
>
>   
>> Martin's reply provides an appropriate response, so nothing to add. But my
>> questions dig deeper: Why do so many (presumably nonstatisticians, but ?)
>> belong to this R^2 religion? Is it because:
>>
>> 1) This is what they are taught in their Stat 101 courses by statisticians?
>> 2) ... by "pseudo"statisticians in their own professions (no disrespect
>> intended here -- just want to make a clear distinction)?
>> 3) It's the prevailing culture of their discipline (journal requirements,
>> part of their standard texts, etc.)?
>>     
>
> Good point. Speaking from a clinical perspective: It is because many 
> journals (British are the exception) ask medical reviewers to do the
> statistical reviewing within 5 minutes. They use the following formula 
> to assess the quality of the paper (weights may vary):
>
> q(paper) = 10* n(pvalues) + 5*n(R^2) + 3.5*n(Error Bars)
>
> Values above 300 qualify for immediate acceptance, and Journals
> like Lancet, New English and British Journal of XXX provide
> professional advice.
>
> The first two are well known, the last is my special combat area.
> Glucose values measured every 2 minutes look like lice-comb, and nobody
> cares about the meaning.
>
> Dieter
>
>   
A very good reply, and the quality formula is probably too close to the 
truth to be funny. Some of the answers given to the people who petition 
the list for help seem to loftily ignore the fact that the petitioners 
are more concerned with getting their paper accepted or their salary 
paid or their dinner cooked than with the opinions of those not so 
motivated about the existential significance of R^2. They may, like your 
humble correspondent, be well aware of the failings of R^2, but be 
unable to conduct a just and noble campaign against the editor, boss or 
chef who demands it. I have just returned from a meeting in which the 
chief investigator was demanding more "user friendliness", despite the 
fact that this clever marketing ploy had turned much of her previous 
data to random numbers. I dunno, it beats me.

Jim