You can contact the school and ask questions about the interview process, although the following is usually provided before the interviews.
- Who are the interviewers
- faculty
- students
- administrators of the school
- How many are there
- What is the school looking for in its students
Prepare for the interview.
- Practice with faculty, other students, etc.
- Re-read your personal statement
- Review your research experiences so that you can discuss the research
- Dress appropriately and comfortably
Ask questions both to inform yourself and to demonstrate an interest in the school (otherwise why go?)
- Coursework - required and elective?
- Rotations - why, how many?
- Other hurdles - prelims, qualifying exams?
- Financial aid package, how much, how long, what are the sources?
- Teaching opportunities versus TAing to finance grad school?
- Research opportunities?
- Average time to degree?
- Outcome of graduates?
Pay attention to the environment while you are there.
- Are students and faculty readily available to meet with you when you visit?
- Do students seem happy to be in the program/school?
- Is the atmosphere and culture what you want/need?
Be aware that you are being evaluated the entire time you are on the campus, not just during the one-on one faculty interviews.