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| From | Nick Cox <njcoxstata@gmail.com> |
| To | statalist@hsphsun2.harvard.edu |
| Subject | Re: st: Observations differ |
| Date | Sun, 23 Sep 2012 13:18:39 +0100 |
I imagine one model is using fewer observations because of missing values in one or more predictors, a problem, which doesn't bite for the other model. Or there could be problems if predictors are constant. A strategy includes 0. Look carefully at the structure of missing values. See e.g. -misstable-, -nmissing- (SJ). 1. Identify the model using fewer observations. 2. Define gen used = e(sample) after fitting that model. 3. Fit the other model using ... if used 4. Compare fits if possible. Nick On Sun, Sep 23, 2012 at 1:02 PM, Shittu, Aminu <ameen_vet@yahoo.com> wrote: > I am trying to compare, using likelihood ratio test, between the full and reduced model in a random effect logistic regression; but the output is saying "observations differ: 3356 vs. 3583." How can I handle this problem, please. * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/