This is highly dependent on the group, but all my communication was through the intern (which I thought was a bit odd), who also ended up interviewing me with the boss. The interview was alright; mostly fit questions. Since it's PWM, you won't have to know models or anything like that, but I do suggest being very up front about asking the employer what the position entails; otherwise, you may be stuck doing grunt work that's worse than cold-calling.