[R] correlation coefficient

[Dieter Menne]

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