When I use the results in Course Mastery Progress - Activity Overview

It allows me to see who needs this lesson, so I don't give students busy work.  I give students who have mastered the topic.  The problem is, when I hit assign, the names are all covered.

One fix could be to allow me to move the popup.

Another, and a really nice addition.
If you wanted to really make this easier, have options that we could check:
[] All Students:
[] Not Started:
[] Attempted:
[] Familiar:
[] Proficient:
[] Mastered:

That would improve teacher accuracy for assignments.