Re: [R] can I do this with R?

From: Frank E Harrell Jr <>
Date: Wed, 28 May 2008 12:01:48 -0500

Smita Pakhale wrote:
> Hi Maria,
> But why do you want to use forwards or backwards
> methods? These all are 'backward' methods of modeling.
> Try using AIC or BIC. BIC is much better than AIC.
> And, you do not have to believe me or any one else on
> this.

How does that help? BIC gives too much penalization in certain contexts; both AIC and BIC were designed to compare two pre-specified models. They were not designed to fix problems of stepwise variable selection.


> Just make a small data set with a few variables with
> known relationship amongst them. With this simulated
> data set, use all your modeling methods: backwards,
> forwards, AIC, BIC etc and then see which one gives
> you a answer closest to the truth. The beauty of using
> a simulated dataset is that, you 'know' the truth, as
> you are the 'creater' of it!
> smita
> --- Charilaos Skiadas <> wrote:
>> A google search for "logistic regression with
>> stepwise forward in r"
>> returns the following post:
>> Haris Skiadas
>> Department of Mathematics and Computer Science
>> Hanover College
>> On May 28, 2008, at 7:01 AM, Maria wrote:
>>> Hello,
>>> I am just about to install R and was wondering
>> about a few things.
>>> I have only worked in Matlab because I wanted to
>> do a logistic
>>> regression. However Matlab does not do logistic
>> regression with
>>> stepwiseforward method. Therefore I thought about
>> testing R. So my
>>> question is
>>> can I do logistic regression with stepwise forward
>> in R?
>>> Thanks /M
>> ______________________________________________

Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University

______________________________________________ mailing list
PLEASE do read the posting guide
and provide commented, minimal, self-contained, reproducible code.
Received on Wed 28 May 2008 - 18:02:19 GMT

Archive maintained by Robert King, hosted by the discipline of statistics at the University of Newcastle, Australia.
Archive generated by hypermail 2.2.0, at Thu 29 May 2008 - 05:30:43 GMT.

Mailing list information is available at Please read the posting guide before posting to the list.

list of date sections of archive