Re: st: Stata vs SPSS

[Ron�n Conroy <rconroy@rcsi.ie>]

On 16 DF�mh 2006, at 19:17, Richard Williams wrote:

> At 11:45 AM 10/16/2006, Georgeta Vidican wrote:
> > hi there,
> > try statistics/nonparametric/binomial
> > i hope it works.
> > georgeta
> I don't think that gives you the confidence interval though - at  
> least it didn't as of SPSS 12.  My comparisons of how SPSS and  
> Stata handle this sort of problem can be found in
What I meant was a simple descriptive statistic

. ci loneliness, bin wil

                                                         ------  
Wilson ------
    Variable |        Obs        Mean    Std. Err.       [95% Conf.  
Interval]
------------- 
+---------------------------------------------------------------
  loneliness |       1337    .3522812    .0130639        . 
3271329     .378276


Stata gives the proportion of people who are lonely and the  
confidence interval. I could not get SPSS to give me the confidence  
interval and, a couple of years ago, I wrote to tech support to ask  
how you did it.

They told me that SPSS didn't calculate the confidence interval for a  
proportion but showed me how it was easy to obtain this, giving me  
the textbook formula for the standard error of a proportion.

I found this incredible, since any fule kno that using the standard  
error formula will produce confidence intervals that are too wide and  
may well exceed the range 0-1.

Stata, on the other hand, embraced Wilson and Jeffreys confidence  
intervals almost instantly  the methods were shown to be the best  
available - they were slightly beaten to it by Nick Cox. And Stata  
has had a confidence interval command for a proportion since I  
started using it (Stata 3).

If it's for social scientists, why does SPSS not have confidence  
intervals for percentages? These aren't exactly alpha geek stuff...

=========
Ron�n Conroy
Royal College of Surgeons in Ireland
rconroy@rcsi.ie
+353 (0) 1 402 2431
+353 (0) 87 799 97 95
www.flickr.com/photos/ronanconroy




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