(I didn't interview for administrative assistant, it was just the closest title this site had to choose from.)
I applied online, and got a call to schedule a phone interview... then a secretary called to schedule an interview with the manager who was looking to fill the position (the person i'd be working for). We got along great and he was super nice. I was called back a week later for an interview with both him and HIS boss (one of the higher up executives). The executive acted like I was imposing on his time, and only asked me some standard interview questions he memorized off of Google (with a lot of "uhm~~~"'s in between). I was told they were interviewing lots of other candidates and the executive said he had one specific one that he liked coming in later that week to interview (so he had already made up his mind before even meeting me).