Re: [R] predictive accuracy

2011-05-31 Thread Marc Schwartz
8:55 PM > To: gunter.ber...@gene.com; El-Tahtawy, Ahmed > Cc: r-help@r-project.org > Subject: RE: [R] predictive accuracy > > >> Date: Thu, 26 May 2011 13:50:15 -0700 >> From: gunter.ber...@gene.com >> To: ahmed.el-taht...@pfi

Re: [R] predictive accuracy

2011-05-31 Thread El-Tahtawy, Ahmed
area of using R to solve challenging issues. Best Regards Ahmed -Original Message- From: Mike Marchywka [mailto:marchy...@hotmail.com] Sent: Thursday, May 26, 2011 8:55 PM To: gunter.ber...@gene.com; El-Tahtawy, Ahmed Cc: r-help@r-project.org Subject: RE: [R] predictive accuracy

Re: [R] predictive accuracy

2011-05-26 Thread Mike Marchywka
> Date: Thu, 26 May 2011 13:50:15 -0700 > From: gunter.ber...@gene.com > To: ahmed.el-taht...@pfizer.com > CC: r-help@r-project.org > Subject: Re: [R] predictive accuracy > > 1. This is not about R, and should be taken off list

Re: [R] predictive accuracy

2011-05-26 Thread Bert Gunter
Al > > -Original Message- > From: Marc Schwartz [mailto:marc_schwa...@me.com] > Sent: Thursday, May 26, 2011 10:54 AM > To: El-Tahtawy, Ahmed > Cc: r-help@r-project.org > Subject: Re: [R] predictive accuracy > > > On May 26, 2011, at 7:42 AM, El-Tahtawy, Ahme

Re: [R] predictive accuracy

2011-05-26 Thread El-Tahtawy, Ahmed
...@me.com] Sent: Thursday, May 26, 2011 10:54 AM To: El-Tahtawy, Ahmed Cc: r-help@r-project.org Subject: Re: [R] predictive accuracy On May 26, 2011, at 7:42 AM, El-Tahtawy, Ahmed wrote: > I am trying to develop a prognostic model using logistic regression. I > built a full , approximate model

Re: [R] predictive accuracy

2011-05-26 Thread Marc Schwartz
On May 26, 2011, at 7:42 AM, El-Tahtawy, Ahmed wrote: > I am trying to develop a prognostic model using logistic regression. I > built a full , approximate models with the use of penalization - design > package. Also, I tried Chi-square criteria, step-down techniques. Used > BS for model valida

Re: [R] predictive accuracy

2011-05-26 Thread Claudia Beleites
Al, I'd redo everything and report in the paper that your peculiar predictor was contributing strongly to models that were built without excluding this predictor. This is an important information: your models get "confused" by the predictor (I'd consider this a lack of a certain kind of robus

[R] predictive accuracy

2011-05-26 Thread El-Tahtawy, Ahmed
I am trying to develop a prognostic model using logistic regression. I built a full , approximate models with the use of penalization - design package. Also, I tried Chi-square criteria, step-down techniques. Used BS for model validation. The main purpose is to develop a predictive model for