Both situations can occur. The two places I've interviewed thus far ranks candidates with their respective point systems. So GPA, GRE, References, Interview scores, etc... are factored in a formula and then that number is used to rank you. So for example, if your GPA is low, but they still invited you, you must have a phenomenal interview score or so to be offered a spot. So yes, for some programs, you'll be at a disadvantage if one of your "numbers" are low going into the interview. hope that helps