I am a student at UABSO, and can try to provide you with a little insight into the interviewing process. Interviews are conducted on Tuesdays and Fridays. You will interview with a relatively small group of about 4-8 people, that is to say there are 4-8 other people being interviewed on the day you interview, they will of course not be in the room with you while you are being interviewed. For me the interview was relatively laidback. If the interview is still the same as last year, there are two main interviews, one with a panel of 3-4 people from the admissions committee, and another open file, 1 on 1, interview. In addition to the interviews a student gives a tour of the school, you will eat lunch, and there is a short discussion on financial aid.
Overall the process is relatively painless, and if you are not too nervous can be quite fun. Just make sure to relax, and give the best and most honest representation of yourself as you possibly can.
I wish you the best of success.