R help - Nov 2001 - models for polytomous data

Hi all

I have a dataset whose response is a categorical variable of the
ordinal scale type (6 levels).
I'm interested in building classification models, and I'm wondering if
there is something implemented in R (or its packages) that I'm not aware
of, to treat the ordinal scale measurements straightforwardly. I can think
of the alternative of building a conditional (hierarchical) binomial model
by glm() or other binary classifiers, but besides that I'm kind of at
a loss.
(I'm familiar with classification methods for nominal scales, I haven't 
seen much for the ordinal kind).
thanks in advance

claudia

-------------------------------------------------------------------------
claudia tebaldi                                  NCAR  RAP
project scientist                                P.O. Box 3000
(303) 497-2830                                   Boulder, CO 80307
--------------------------------------------------------------------------





-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at
stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._

>>>>> "Claudia" == Claudia Tebaldi <tebaldi at
rap.ucar.edu> writes:
    Claudia> I have a dataset whose response is a categorical variable of the
    Claudia> ordinal scale type (6 levels).

    Claudia> I'm interested in building classification models, and
I'm
    Claudia> wondering if there is something implemented in R (or its
packages)
    Claudia> that I'm not aware of, to treat the ordinal scale
measurements
    Claudia> straightforwardly. I can think of the alternative of building a
    Claudia> conditional (hierarchical) binomial model by glm() or other
binary
    Claudia> classifiers, but besides that I'm kind of at a loss. 
(I'm
    Claudia> familiar with classification methods for nominal scales, I
haven't
    Claudia> seen much for the ordinal kind).  thanks in advance

> help(polr, package = MASS)
polr                  package:MASS                  R Documentation

Proportional Odds Logistic Regression

Description:

     Fits a proportional odd logistic regression model to an ordered
     factor response.

Usage:

     polr(formula, data=NULL, weights, start, ..., subset, 
          na.action=na.fail, contrasts=NULL, Hess=FALSE)

....

-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !)  To: r-help-request at
stat.math.ethz.ch
_._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._