On Mon, 5 Apr 2004, Schmidt.Matthias (FORST) wrote:

> I have used the multinom function from the nnet library to estimate
> probabilties for different levels of a nominal variable:
> 
> predict(object,type="probs")
> 
> Is  there any possibility to estimate confidence intervalls for the
> probabilties with the multinom function?

No, as confidence intervals (sic) apply to single parameters not
probabilities (sic).  The prediction is a probability distribution, so
the uncertainty would have to be some region in Kd space, not an interval.

Why do you want uncertainty statements about predictions (often called
tolerance intervals/regions)?  In this case you have an event which
happens or not and the meaningful uncertainty is the probability
distribution.  If you really have need of a confidence region, you could
simulate from the uncertainty in the fitted parameters, predict and
summarize somehow the resulting empirical distribution.


-- 
Brian D. Ripley,                  [EMAIL PROTECTED]
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595

______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html

Reply via email to