<p>From what ive heard (My uncle is a Penn interviewer)they have one look at your application and see if you haven’t elaborated on any aspects or if they feel that there is more to you than what your application states. If so, you get an interview ASAP. For the others its by chance. The regional interviewer gets a full list of ALL applicants and it is divided amongst the interviewers based on your major. The individual interviewers try to interview as many people in their last as possible. But obviously a few get left out.
Thus, if you did not get an interview its because your application well presented and that you fell short on a bit of luck. Don’t sweat it.
BOL</p>