If you want to see how far through a course a student of yours is you can do it within your Membership Dashboard.
Use either the student search function or search manually through the membership or course that the student belongs to in order to locate them.
Click on the students name. You will then see a list of the courses the student belongs to. Beside the names of the courses the student is enrolled in you'll see a progress bar. This bar shows the % of the course your student has completed:
Also beside this bar you can see exactly what date your student last logged into that particular course.
Use this information to assess how far through a student has got through your course, in reviewing refund requests you can see if your student has given the course a fair go, you could also reward students who have completed a particular course.