multinomial regression warnings

[Heba Dabbour]

I have a question about multinomial regression using spss. I have a dependent variable of 3 categories and other independent variable which are also categories and on scale (age). I used automatic coding using spss then I run the the multinomial regression and get this warning" Unexpected singularities in the Hessian matrix are encountered. This indicates that either some predictor variables should be excluded or some categories should be merged"
and also this warning" There are 372 (62.9%) cells (i.e., dependent variable levels by subpopulations) with zero frequencies."

I don't have empty cells.
Can anyone help me please as how to proceed.

[Rich Ulrich]

On Sun, 12 Jan 2020 10:21:37 -0800 (PST), Heba Dabbour

Post by Heba Dabbour
I have a question about multinomial regression using spss. I have a dependent variable of 3 categories and other independent variable which are also categories and on scale (age). I used automatic coding using spss then I run the the multinomial regression and get this warning" Unexpected singularities in the Hessian matrix are encountered. This indicates that either some predictor variables should be excluded or some categories should be merged"
and also this warning" There are 372 (62.9%) cells (i.e., dependent variable levels by subpopulations) with zero frequencies."
I don't have empty cells.
Can anyone help me please as how to proceed.

If you think that you have no empty cells, /and/
SPSS thinks that you have 372 empty cells, /then/
you and the procedure have a /major/ disagreement
about the design and the data.

That is the error message you need to deal with.
How many cells do you think you have, in all?

590+ is a big, big number of predictors; I have
doubts about the efficacy of such a design,
generally speaking, even if your sample is the
ten or twenty thousand or more it needs.

If you used "automatic coding" that caused one
continuous variable to be treated as categories,
that could generate this surprise.

- If the above doesn't let you solve your problem,
please post your SPSS code with your further
question.

[Rich Ulrich]

On Sun, 12 Jan 2020 18:23:42 -0500, Rich Ulrich

Post by Rich Ulrich
If you used "automatic coding" that caused one
continuous variable to be treated as categories,
that could generate this surprise.

Or, more precisely - If somebody's "automatic coding"
sees a categorical variable with /whatever/ number of
values between 1 and 90, it /might/ decide use the largest
value and - thus - there will be 90 categories.

I think it is "AUTORECODE" that will produce categories
of 1-k in a new variable, with the original values (originally
either numeric or string) as Value Labels.