So, I got an email this morning from a POI at one of my top choices asking for a chat tomorrow via Skype. The prof said he has been looking at my application with great interest.
He used the word 'chat' rather than 'interview', so I'm not sure if it's a formal interview or not, but in either case I'll be preparing for that.
Does anybody have any tips? I've done job interviews before, even interviewed people for jobs, but I haven't had a grad school interview before.