My response var is a binary variable. In the predictor variable i have a type variable with levels as l1,l2,l3,l4. And when i run a logit (glm(redonse ~ type, family = "binomial"), Some levels of type variable turn out to be insignificant. i.e typel2 comes out to be insignificant. So my question is that, could i drop a that level for a variable somehow. ie i drop typel2 (treat typel2 as NULL or so)and then run the glm. i hope the question is clear.