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: Bootstrapping question


From   "Seed, Paul" <[email protected]>
To   "[email protected]" <[email protected]>
Subject   Re: st: Bootstrapping question
Date   Fri, 8 Feb 2013 12:23:24 +0000

If Henry Ilan wants a finite population correction 
to the CI for his proportion (we are told 
the population is only 140) , he can use the 
-svy- commands.  The CI for this particular population 
size is very similar to the Wilson one.

The following demonstrates:

****************************
* Start Stata code *

* Set up sample
clear
set obs 27
gen event = _n <= 14

* CI by methods already discussed
ci event , bin
ci event , wilson bin

* Set up sampling structure
gen id = 1
replace id = _n
gen pop = 140
svyset id , fpc(pop)

* CI with FPC
svy : proportion  event

* CI without FPC
svyset id 
svy : proportion  event

****************************
* End Stata code *
****************************

Paul T Seed, Senior Lecturer in Medical Statistics, 
Division of Women's Health, King's College London
Women's Health Academic Centre, King's Health Partners 
(+44) (0) 20 7188 3642.


*********************************************
> On Wed, Feb 6, 2013 at 8:53 PM, Ilian, Henry (ACS)
> <[email protected]> wrote:
>> The sample size 1s 27, which is the largest number the case readers can handle in the amount of time allotted. The population the sample is drawn from is 140. To get a confidence interval for proportion I used Lenth's on-line application, http://homepage.cs.uiowa.edu/~rlenth/Power/. Since the items have different proportions, there are several confidence intervals. Using 50% as the proportion (meaning that for a particular item, 50% of the sample were awarded the highest ordinal rating, and the other 50% were awarded other ratings), I got a margin of error of 17.3%. For a proportion of 70%, the margin of error is 16%, etc.



*
*   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