I sat around a table with about 6 other people. At the start of the interview I was asked to give a 20 minute lesson that would be appropriate for a lower division mechanical engineering class. I was told about this part in advance so I was able to prepare. During the lesson, the interviewers asked me questions just like they would in class. After the lesson they interviewers each asked me a succession of 12 prewritten questions. They were not allowed to deviate in their questioning but I was encouraged to elaborate on my answers.