Are they conducted with every applicant or only with possible/viable candidates?
As far as Harvard will tell us, the opportunity to do an interview is determined by geographic location and availability. If there is an alumni in your area who is willing and able, Harvard will attempt to arrange an interview.
As far as they'll admit, they do not screen you to see if it will be a waste of time. It's just an availability thing.
Not everyone gets an interview, simply because resources (willing alumni and such) are limited.
If you're entire state is populated by Harvard Alumni and you don't get an interview, though, we'll know they've been lying and we'll sue them and go to Yale for good measure lol!
Best to you!
They try to offer them to every applicant, but they're limited by interviewer availability! So it does end up tending to be somewhat random.
To keep this community safe and supportive:
Thank you!