Some people have two different accounts, typically one as a student and another one as an employee. When one of these, e.g. Gabriël, is TAing in your course, assigning them as graders becomes a gamble, since you can’t distinguish the proposed accounts.

Submitted by Guido Wachsmuth on 17 November 2015 at 11:51

The interface should display the email address next to the name; this should also help avoiding tricking an instructor to add someone who is spoofing their name.