I was contacted through on-campus recruiting and then I emailed my application (cover letter and resume). immediately I set up a phone interview and then one week later scheduled an on-campus interview. 3M had a travel agent contact me and take care of all of the arrangments. I interviewed with seven other candidates and did group questions and individual interviews (3 rounds for about 30 minutes each). It was a pretty easy morning and not too many difficult questions. The plant tour was a bit dull.