I applied online and was called by a recruiter the next day with an initial phone interview to set up my interview in Cleveland. She asked a few questions such as "what made you choose this position" or "tell me about your internship/classes". It was very basic and easy, then they pay for mileage to drive to Cleveland or fly if you are far enough away. Once you get to Cleveland, they have a "Welcome Reception" where all the people that are interviewing on the same day are invited to attend. Go to this and treat it as an interview (some of the candidates will probably send an email as a recap to the program director).
The didn't ask me direct questions about how old I was or if I had kids/married but they were sneaky about it.
One interview was quite frankly terrible, there was a woman and a man in the interview. When I walked in the room, the woman had a terrible attitude already and was rude the entire time. She made rude and condescending comments the whole time. After speaking to other candidates, they had similar experiences with this round. I'm not sure if it was her personality or if she was seeing how we could handle arrogance.