What makes you a resident of a county?

I just received a Juror Qualification Questionnaire from the "State of New York Unified Court System" and one of the questions is "are you a resident of Suffolk County, NY?". I go to college in Suffolk County and I registered to vote here - which is how they got my name - however, I'm from Pennsylvania. I live on campus, but I've only been here since August '08. Did my registering to vote make me a resident of Suffolk County?