Bookmark and Share

Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

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


From   "David Radwin" <[email protected]>
To   <[email protected]>
Subject   RE: st: RE: Moderation effect by splitting the sample
Date   Fri, 21 Dec 2012 09:02:24 -0800 (PST)

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: [email protected] [mailto:owner-
> [email protected]] On Behalf Of Ebru Ozturk
> Sent: Friday, December 21, 2012 12:45 AM
> To: [email protected]
> 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: [email protected]
> > To: [email protected]
> > 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: [email protected] [mailto:owner-
> > > [email protected]] On Behalf Of Ebru Ozturk
> > > Sent: Thursday, December 20, 2012 11:42 AM
> > > To: [email protected]
> > > 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/


© Copyright 1996–2018 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   Site index