[R] cross validation and CART

[Liaw, Andy]

> From: Laure Maton
> 
> Hello,
> I would like to know if the classification trees i built with 
> my data are 
> predictive or not.
> Could you explain me how to do that?
> Thanks
> Laure Maton

If you are talking about the particular tree models that you built from the
data, you will need independent test set to evaluate prediction performance.
If you want to know if the _algorithm_ can produce models that are
predictive, you can use something like cross validation.  See the errorest()
function in the `ipred' package, for example.

Andy