Entry level engineer position at 3M. Usually consist of an on-campus interview and/or a phone interview followed by an on-site interview. The on-site interview consists of a management interview, a peer interview, and a tour of the manufacturing location. Depending on the location, a lunch "interview" and tour of the surrounding area will occur afterwards.
The O2 on-site interviews follow a standardized list of questions. This means that if you interview at more than one location, you'll get the same questions at both places. There are no trick questions and no technical questions that I can remember. Each interview lasts about an hour.
Tips:
Show up on-time and ready to go.
Remember that everything done on-site is part of the interview (i.e. how you act at lunch and on the tours can impact whether an offer is made).