I had an interview with a surgeon and a medical student, while some had two faculty members, either MD or PhD. They ask basic interview questions because it is closed-file so be prepared for that. For me, this interview was much more conversational than other interviews I have been to, but I can't say that its a good or bad thing since every school looks for different things. But you must come up with at least three intelligent questions to ask your interviewers, they seem to almost expect it from you. Again, be relaxed!