Dartmouth Interview

So does anyone know how interviews are arranged with alumni? Are the alumni given a choice and they randomly select which ones to reach out to? And if so, how do they decide which ones? Are they given information about the applicant to see which ones are most promising or something?

Interviewees are randomly assigned based on the number of interviews someone wants to do per admission cycle. The only information given to interviewers is contact information, intended major, and high school name.