Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

st: RE: RE: RE: Bootstrapping and t-tests


From   "Nick Winter" <nwinter@policystudies.com>
To   <statalist@hsphsun2.harvard.edu>
Subject   st: RE: RE: RE: Bootstrapping and t-tests
Date   Wed, 12 Jun 2002 13:18:56 -0400

> -----Original Message-----
> From: Siyam,AA (pgr) [mailto:A.A.Siyam@lse.ac.uk] 
> Sent: Wednesday, June 12, 2002 1:07 PM
> To: statalist@hsphsun2.harvard.edu
> Subject: st: RE: RE: Bootstrapping and t-tests
> 
> 
> Sorry that was a typing error of mine - still the error 
> message I get tells me:
> 
>  bs "ttest prert=postrt"  "_b[prert] _b[postrt]", reps(50) n(10)
> command:     ttest prert=postrt
> statistics:  _b[prert] _b[postrt]
> error in statistic: _b[prert]
> r(198);
> 


The t-test command does not return results in _b[varname].  In the
syntax you are using, you should type:

	. bs "ttest prert=postrt" "r(mu_1) r(mu_2)", reps(50) n(10)

You can find out how a command returns results by typing -return list-
(for r-class commands) or -estimates list- (for estimation commands).

I imagine you probably want to pick up something like "r(p)" (the
p=level of the test), or "r(t)", the t-ratio for the ttest.  As it
stands, you are just getting the two bootstrapped mean estimates.

--Nick Winter

*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index