I have been working at University of Oklahoma part-time (More than a year)
One of the best facilities I've ever experienced! The faculty present are driven, yet congenial and are constantly seeking the best opportunities for their students. The department uses an experimental education model so it does not always follow the "semester" schedule, meaning there is flexibility and variety in the content and ways you are learning.
The demand on first year students is rather high. I believe there is a lot of "extra" work that will not have to be repeated in future years, but it makes the first two semesters a drag.
the interview was arranged by the secretary and the full procedure just follows an ordinary interview that one may expect. There was not specific tough questions, since this is not a very competitive position.