There are two cases of students who appear in the 'Excellent Assignment Selection' list.
Students whose assignments have been scored.
Students submitted the assignment and you have not completed the grading, but you have accessed the individual assignment grade entry page by clicking the Student's [Grades] button
Click an assignment, and then click the [Excellent Assignment Selection] button.
You can see the list of students as follows:
The instructor selects an excellent assignment by clicking the check box on the left and clicking the [Excellent Assignment Selection] button.