RE: st: RE: Moderation effect by splitting the sample

[Ebru Ozturk <ebru_0512@hotmail.com>]

I know it is not the best approach but I use tobit and probit regression models. In order to see the interaction effects it seems easier for me. 

 
----------------------------------------
> From: dradwin@mprinc.com
> To: statalist@hsphsun2.harvard.edu
> Subject: RE: st: RE: Moderation effect by splitting the sample
> Date: Fri, 21 Dec 2012 09:02:24 -0800
>
> Ebru,
>
> Again, I don't think this is necessarily the best approach for your
> situation, but amending Nick's code in
> http://www.stata.com/statalist/archive/2012-12/msg00758.html , it would be
> something like this:
>
> sysuse auto
> su weight, detail
> gen byte mysplit = cond(weight >= r(p75), 1, cond(weight <= r(p25), 0, .))
>
>
> David
> --
> David Radwin
> Senior Research Associate
> MPR Associates, Inc.
> 2150 Shattuck Ave., Suite 800
> Berkeley, CA 94704
> Phone: 510-849-4942
> Fax: 510-849-0794
>
> www.mprinc.com
>
>
> > -----Original Message-----
> > From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-
> > statalist@hsphsun2.harvard.edu] On Behalf Of Ebru Ozturk
> > Sent: Friday, December 21, 2012 12:45 AM
> > To: statalist@hsphsun2.harvard.edu
> > Subject: RE: st: RE: Moderation effect by splitting the sample
> >
> > David, thank you. Can you also give the Stata commands for comparing
> upper
> > and lower quartiles?
> >
> > Kind regards
> > Ebru
> >
> > ----------------------------------------
> > > From: dradwin@mprinc.com
> > > To: statalist@hsphsun2.harvard.edu
> > > Subject: st: RE: Moderation effect by splitting the sample
> > > Date: Thu, 20 Dec 2012 11:50:45 -0800
> > >
> > > Ebru,
> > >
> > > I can't say for sure without knowing more about what you are trying to
> > do,
> > > but regarding splitting continuous variables, see this post and the
> > > references therein:
> > >
> > > http://www.stata.com/statalist/archive/2011-03/msg00154.html
> > >
> > > If you do split the variable anyway, consider comparing upper and
> lower
> > > terciles or quartiles (and not the upper and lower halves as a
> previous
> > > email intimated) to minimize loss of efficiency:
> > >
> > > Gelman, A., & Park, D. K. (2009). Splitting a predictor at the upper
> > > quarter or third and the lower quarter or third. The American
> > > Statistician, 63(1), 1-8.
> > > http://www.stat.columbia.edu/~gelman/research/published/thirds5.pdf
> > >
> > > David
> > > --
> > > David Radwin
> > > Senior Research Associate
> > > MPR Associates, Inc.
> > > 2150 Shattuck Ave., Suite 800
> > > Berkeley, CA 94704
> > > Phone: 510-849-4942
> > > Fax: 510-849-0794
> > >
> > > www.mprinc.com
> > >
> > >
> > > > -----Original Message-----
> > > > From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-
> > > > statalist@hsphsun2.harvard.edu] On Behalf Of Ebru Ozturk
> > > > Sent: Thursday, December 20, 2012 11:42 AM
> > > > To: statalist@hsphsun2.harvard.edu
> > > > Subject: st: Moderation effect by splitting the sample
> > > >
> > > >
> > > > Dear All,
> > > >
> > > > For non-linear models, I want to test the moderation effect of X
> > > variable.
> > > > Can I test this moderation effect by spliting the sample according
> to
> > X
> > > > variable (moderator)?
> > > >
> > > > Kind regards
> > > > Ebru
> > >
> > > *
> > > * For searches and help try:
> > > * http://www.stata.com/help.cgi?search
> > > * http://www.stata.com/support/faqs/resources/statalist-faq/
> > > * http://www.ats.ucla.edu/stat/stata/
> > *
> > * For searches and help try:
> > * http://www.stata.com/help.cgi?search
> > * http://www.stata.com/support/faqs/resources/statalist-faq/
> > * http://www.ats.ucla.edu/stat/stata/
> *
> * For searches and help try:
> * http://www.stata.com/help.cgi?search
> * http://www.stata.com/support/faqs/resources/statalist-faq/
> * http://www.ats.ucla.edu/stat/stata/ 		 	   		  
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/