I was super-nervous for this interview, and thought it was terrible at the time. Looking back, the two interviews I had (1 a PhD researcher, 1 an oral radiologist) were really nice and asked very fair questions. At the time though, I overanalyzed everything. My advice is to just be yourself, and answer the questions truthfully. Try and relax if you can.
Harvard isn't all about "research" as some people have suggested. They really want well-rounded people with a range of experiences. Travel, leadership, non-science interests, etc are all important. Also, I think they want people who have explored/considered other health fields.
💬 Interview Process
How did you prepare for the interview?
SDN interview feedback, read Harvard website, studied info they sent me pre-interview
What impressed you positively?
High quality of the students there. Administration really cares about the students, and wants all of them to do well. Integration of medical and dental schools the first two years with same grading curves; emphasizes the idea that dentistry is a subspecialty of medicine. Opportunities to get involved in all sorts of research projects. Success of harvard students matching into competetive specialty programs. I did not meet one person that I considered arrogant or snotty. People were all very laid-back.
What impressed you negatively?
Not so sure the PBL thing is for me. But then, I don't really know what program would be good for me!