At 08:02 AM 11/12/2012, Linda.Kampata@student.uib.no wrote:
Thanks Nick,
I managed to get the brant command from a lower version of the spost.
However, when i run the brant command I get the following error message.
. brant, detail
not all independent variables can be retained in all binary logits
brant test cannot be computed
r(999);
What does this error message mean in a less technical language? When I
click on the r(999) I get a stata dialogue message which reads "no
entries found for search on "r(999)"."
Thanks,
Linda
The -brant- command takes your ordinal dependent variable,
dichotomizes it in various ways, and then runs a series of logistic
regressions. So, if your DV has 4 values, the first logistic
regression is category 1 versus categories 2, 3, 4. Then, it does 1 &
2 versus 3 & 4, and finally, 1, 2, 3 vs 4. Your error message is
telling you one or more of those logistic regressions can't be run
without dropping some variables. Perhaps category 1 only has 7 cases
and your model has 8 variables. My guess is you will need to simplify
the model or combine categories. You can run the logistic regressions
yourself to pinpoint exactly where and why the problem is occurring.
But I would start just by doing a frequency of the DV to see if any
categories (especially the first and the last) have very small
frequency counts.
