Why don't I see all of my students assigned to the assignment in Realize?

Realize does not add students to an assignment until they open the assignment in the LMS course. Once students open the assignment, Realize automatically adds them to the assignment and their status is set to In Progress.

In the example below you can see one student has completed the Solve & Share assignment and two students have opened the assignment but have no completed it. Students who have not opened the assignment in Schoology will not appear under Not Started.