I would say that depends more on the culture of the institution than anything. "Professor" is acceptable at some places, first name is the norm at others, and

I would say that depends more on the culture of the institution than anything. "Professor" is acceptable at some places, first name is the norm at others, and "Mr./Mrs./Ms." at still others. When I was a grad student, I made a point when introducing myself on day 1 that I was not a professor, so please don't call me "Professor Pmiller2" Then, I said something about "if you call me "Mr. Pmiller2," I'm going to wonder if my dad is standing behind me, so, please just call me "$FIRSTNAME." That was pretty much the standard where I was among people in my department (grad students = first names).