Darin Brooks wrote:
Glad you were amused.

I assume that "booking this as a fortune" means that this was an idiotic way
to model the data?

Dieter was nominating this for the "fortunes" package in R.  (Thanks Dieter)


MARS?  Boosted Regression Trees?  Any of these a better choice to extract
significant predictors (from a list of about 44) for a measured dependent
variable?

Or use a data reduction method (principal components, variable clustering, etc.) or redundancy analysis (to remove individual predictors before examining associations with Y), or fit the full model using penalized maximum likelihood estimation. lasso and lasso-like methods are also worth pursuing.

Cheers
Frank


-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Ted Harding
Sent: Saturday, September 27, 2008 4:30 PM
To: [EMAIL PROTECTED]
Subject: Re: [R] FW: logistic regression



On 27-Sep-08 21:45:23, Dieter Menne wrote:
Frank E Harrell Jr <f.harrell <at> vanderbilt.edu> writes:

Estimates from this model (and especially standard errors and
P-values)
will be invalid because they do not take into account the stepwise procedure above that was used to torture the data until they confessed.

Frank
Please book this as a fortune.

Dieter

Seconded!
Ted.

--------------------------------------------------------------------
E-Mail: (Ted Harding) <[EMAIL PROTECTED]>
Fax-to-email: +44 (0)870 094 0861
Date: 27-Sep-08                                       Time: 23:30:19
------------------------------ XFMail ------------------------------

______________________________________________
R-help@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.
No virus found in this incoming message.
Checked by AVG - http://www.avg.com

6:55 PM

______________________________________________
R-help@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 Chair           School of Medicine
                     Department of Biostatistics   Vanderbilt University

______________________________________________
R-help@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.

Reply via email to