I’m sure it varies by school and POI, but here’s my experience: I had an interview and it was very laid back. POI was very excited about my writing sample and wanted to talk a bit about how I wrote that. They talked generally about the program for a bit, and gave me an opportunity to ask questions. I felt like it was less of an “interview” and more of the POI trying to get a feel for my interest/enthusiasm for the program before making an offer, as well as trying to “sell” the program to me a bit. I was pretty nervous beforehand but it was really easy: we really just talked about things that I was interested in and knew well, so it wasn’t stressful at all. Good luck, and remember that they’re trying to impress you just as much as you want to impress them.