Re: st: Binomial confidence intervals

[Constantine Daskalakis <C_Daskalakis@mail.jci.tju.edu>]

At 01:24 PM 9/7/2004, Richard Williams wrote:
> The -ci- command includes several options for computing binomial 
> confidence intervals: exact (the default), wilson, agresti and 
> jeffreys.  Just so I am clear on these, is "exact" really really really 
> exact?  Am I correct in guessing that "exact" can be the most difficult to 
> do by hand, and the others are therefore approximations that are somewhat 
> easier to calculate if you don't have a computer?  Is there any reason I 
> would not want to use "exact", other than perhaps to replicate a 
> calculation done using one of the other methods? Thanks for any insights.
>
>
> -------------------------------------------
> Richard Williams, Notre Dame Dept of Sociology
> OFFICE: (574)631-6668, (574)631-6463
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> EMAIL:  Richard.A.Williams.5@ND.Edu
> WWW (personal):    http://www.nd.edu/~rwilliam
> WWW (department):    http://www.nd.edu/~soc
I remember checking this at some point. The "exact" option indeed gives the 
exact binomial confidence interval (which requires an iterative algorithm 
to get the limits, eg, bifurkation algorithm). StatXact calls this the 
"Clopper-Pearson" interval.

I have no idea what these other intervals are and why we need them. I was 
not aware of those  options and they are not documented in the manual.





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________________________________________________________________
Constantine Daskalakis, ScD
Assistant Professor,
Biostatistics Section, Thomas Jefferson University,
211 S. 9th St. #602, Philadelphia, PA 19107
   Tel: 215-955-5695
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   Email: c_daskalakis@mail.jci.tju.edu
   Webpage: http://www.jefferson.edu/medicine/pharmacology/bio/  
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