R help - Apr 2011 - How to answer the question about transitive correlation?

Hi, everyone. I know it may be a basic statistical question. But I can't
find a good answer.

I have a question raised by one of the reviewers.
Factor A expression was strongly correlated with B expression (chi-square)
in this series. Prior reports by the same authors showed that B expression
strongly correlated with survival (Log-rank). Please provide an explanation
why then were the results not transitive.
Thanks a lot.

*Yao Zhu*
*Department of Urology
Fudan University Shanghai Cancer Center
Shanghai, China*

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> Date: Fri, 22 Apr 2011 11:42:59 +0800
> From: mailzhuyao at gmail.com
> To: r-help at r-project.org
> Subject: [R] How to answer the question about transitive correlation?
>
> Hi, everyone. I know it may be a basic statistical question. But I
can't
> find a good answer.
>
> I have a question raised by one of the reviewers.
> Factor A expression was strongly correlated with B expression (chi-square)
> in this series. Prior reports by the same authors showed that B expression
> strongly correlated with survival (Log-rank). Please provide an explanation
> why then were the results not transitive.

The only explanation that would have any value would require you post the
data and let everyone look at it and any R output would be a benefit too. 
So you compared A and B with one test, 
B vs C with another, cutoff the result at some arbitrary criterion, and
then wonder why some unspeficied test and criterion applied to A vs C
doesn't vote in the majority with the same answer? Changing acceptance
levels
or applying a "correction" after careful shoppping can always
"fix" that
logical inconsistency LOL. Its not hard to plot 3 normal curves on same graph
and see one example of how their overlaps can relate.

I'm not sure what to think but perhaps you could look at stuff like this,

http://en.wikipedia.org/wiki/Path_analysis_%28statistics%29

On 22.04.2011 05:42, zhu yao wrote:
> Hi, everyone. I know it may be a basic statistical question. But I
can't
> find a good answer.
>
> I have a question raised by one of the reviewers.
> Factor A expression was strongly correlated with B expression (chi-square)
> in this series. Prior reports by the same authors showed that B expression
> strongly correlated with survival (Log-rank). Please provide an explanation
> why then were the results not transitive.
I do not understand anything here:

- First of all: Why is this a question on the *R* help mailing list?

- How is "the reviewer"?
- How is "the same authors"?
- Which article are you referring to?
- What is *known* about the relation between the stuff you named "A", 
"B" and "survival"?


Uwe Ligges



> Thanks a lot.
>
> *Yao Zhu*
> *Department of Urology
> Fudan University Shanghai Cancer Center
> Shanghai, China*
>
> 	[[alternative HTML version deleted]]
>
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