I was nervous about attending a group interview at Temple University because I thought I would have to be assertive to be heard in group discussions. However, the interview at Temple was relaxed. It was 3-4 students and two Interviewers (current student, and current faculty). Questions were asked and each applicant took turns answering. In the end most applicants probably felt a little short changed because they really only had about 5-7 min of speaking time. At some points in the interview I chose to comment on something another applicant already said (always positive comments) as a way of trying to include applicants in a group discussion. However, the interviewer kept a format of one question to one applicant. A number of us traveled across the country to be here, and than only spoke at our interview for about five minutes!
I have read the group interview format is chosen to see how well applicants are able to interact with potential classmates and instructors in a group discussion format, and to expedite the interview process. I have heard of other adaptations within a group interview model but this is the only I am directly familiar with. Hope this helps!