Be yourself. Don’t assume it will be a bad interview. Dress nicely, be on time and answer the questions asked. Come with your own questions. Most interviews are for admissions to confirm their impression of you based on your application.
BTW Dartmouth had the most unimpressive info session video that we have seen. I don’t think that is indicative of them as a college but it shows that they are all just people like everyone else.
BTW smile when you meet your interviewer. And good luck!
Alumni interviews don’t carry a ton of weight in the admissions process. Go in without any preconceived notions about the interviewer, be yourself, and it should be just fine.
Thanks for the responses! Sorry for my belated responses (oops) but the interview actually went really well! The alum who interviewed me was thoroughly impressed with my responses, and said that he’d offer his highest recommendation. Thanks again!