I’ve personally probably done over 200 interviews myself for my Ivy alma mater. And the truth is the vast majority of them counted for nothing other than to leave the student feeling good about having spoken to an ambassador from my school.
In the vast, vast majority of cases, a great interview (even a mediocre one) will have no effect. (And again, only a few colleges even CONDUCT interviews, most don’t)
My experience (as a 25+ year interviewer for a school with a tiny admit rate) is this: for most kids, it won’t make ANY difference. The applicants are in three groups: a) shoo-ins (recruited athletes, other “gotta haves” that, barring a felony or something, will receive an offer) – this is only a very small group (~2-3%), b) the vast number who don’t get much traction past the first read. I can imagine ~85%. Then there’s c) that remaining ~10% or so which they need to whittle down by 4/5 — the kids in the grey area. For them, an very good interview MIGHT make a difference.
For group a) and b) who represent the vast bulk of applicants – there is no effect whatsoever.
That being said, I know of students in the “c” category for whom the alumna’s report did tip the scale in the applicant’s favor in the committee’s eyes.
@exwire: Your friend’s app had the positive write up – but it has survivor bias. What you don’t see is the 80% of other glowing write ups but they were affixed to files that got rejected.