I am running a glm family = poisson for count data.
I am not really sure how to interpret my null and residual deviance and haven't found anything else useful to help explain how to actually interpret and what the values mean (aka if my model is an ok fit):
(Dispersion parameter for poisson family taken to be 1) Null deviance: 3429.4 on 4438 degrees of freedom Residual deviance: 1694.6 on 4430 degrees of freedom AIC: 19511
I have done 1 - (residual / null) and got a value of 0.5058611
Does this mean that my R^2 is 0.5? If not, what do these values mean and how to I use them to look at the fit of my model?