Re: [R] R^2 analogue in polr() and prerequisites for polr()

2003-12-08 Thread Christoph Lehmann
many thanks! I was just asking for a r-square analogue, since the students I will present the results to, might like to know, how the measure of fit in an ordinal regression (e.g. the residual deviance) compare to measures they know (from introductory courses to linear regression) (such as the r-sq

Re: [R] R^2 analogue in polr() and prerequisites for polr()

2003-12-08 Thread Prof Brian Ripley
On 8 Dec 2003, Christoph Lehmann wrote: > (1)In polr(), is there any way to calculate a pseudo analogue to the > R^2. Just for use as a purely descriptive statistic of the goodness of > fit? First define the statistic you are interested in! There is an absolute measure of fit, the residual devi

[R] R^2 analogue in polr() and prerequisites for polr()

2003-12-08 Thread Christoph Lehmann
Hi (1)In polr(), is there any way to calculate a pseudo analogue to the R^2. Just for use as a purely descriptive statistic of the goodness of fit? (2) And: what are the assumptions which must be fulfilled, so that the results of polr() (t-values, etc.) are valid? How can I test these prerequisit