Re: probit

Posted by Gary Rosin on Oct 25, 2006; 6:03pm
URL: http://spssx-discussion.165.s1.nabble.com/probit-tp1071648p1071649.html

>I use the Probit analysis in SPSS 12G. I have count data ("response",
>...) vs dosis ("covariate"),.... But the problem is: If I use subgroups for
>different treatments (as "factor" 1 to n) the results differ completely
>compared to the results of separate analyses.

I haven't see a response to this question.  In the probit procedure,
the use of a factor only tests for a change in the intercept.  If you do
a split-file analysis, you can check for effects on the intercept *and*
on the coefficient(s).

Gary