I do alumni interviews for an Ivy League school. They are NOT four hour one on one sessions, for the most part.
My Princeton interview was over three hours long. It was with a local alum who was a research scientist who did a lot of programming. I had a ball. He called me to make sure I got my letter and was disappointed to learn I decided to go somewhere else.
Harvard was very short and superficial and I wrote them off my list as a result.
Ditto MIT. It was almost two hours. I had a lot of questions for him and he said twice during the interview that, "If you don't know this, then MIT might not be the best fit for you."
My longest interview was for Caltech, with a retired professor, and was highly technical, with lots of hard questions that just kept getting harder until we were on stuff I did not know anything about. He'd give me some information and then prod me to guess or to give him my thoughts. Not something I had been asked to do much. I had to stop and think for minutes. I felt intimidated and I thought I flunked it. I didn't. I remember one question in particular, "Have you ever stayed up all night working on something and what was it." That was just one of many questions no one else asked me.
And yes, I know MIT and Caltech are not Ivy League schools, but I wanted to help others understand the interview process at elite colleges from an interviewee's perspective.
