I have a problem when running a logistic regression in SPSS.
My objective is to look whether several variables have an impact on body satisfaction.
One of these independent variables is "diploma" (degree), which stands for the highest diploma that someone has completed.
When I run a logistic regression only with this variable as an independent variable, there is no problem
But when I'm putting "Form of education" in it as another independent variable, 2 of the 3 categories of my variable "diploma" disappear (without taking account of the reference group).
I really don't know what I have to do to solve this problem.
It would be extremely helpfull if someone knew the answer on this.