[R] classification table in logistic regression

[Peter Flom]

Frank E Harrell Jr <f.harrell at vanderbilt.edu> wrote

>Armida,
>
>I regret putting CTABLE as an option on the old SAS PROC LOGIS which was 
>a basis for PROC LOGISTIC.  Classification tables are arbitrary and 
>misleading so I would stay away from them.
>
>You might build a model with and without the variable of interest and 
>plot the two predicted probabilities against each other for more insight 
>than what is provided by a classification table.
>

Frank, 

I agree with 'arbitrary' but why 'misleading'?  Purely for the same sorts
of reasons that histograms can be misleading, or for other reasons, as well?

Plotting the probabilities is an excellent idea, I recommend it often, in a variety
of situations.

Peter

Peter L. Flom, PhD
Statistical Consultant
www DOT peterflomconsulting DOT com