Dependent or not

Hi experts, I have a son of 19 years old who started attending college. Last year he lived in a dorm (out of state) for 4 months and also had a small income for his part-time job.

 

I'm wondering if I need to include him as a dependent like before or not. He had his own income (which is small) with W2, so I think his income also needs to be reported.

 

My guess is that he may get a refund if he files his own tax report, but I would like to know which is the best.