If you've added lessons to your course AFTER your students have completed their course, you may wish to reset their completion percentage.
NOTE: Recalculating your student's course completion should only be used when adding content to your courses. If you have enabled Course Completion Email Notifications and an existing student would be 100% complete your course after the re-calculation, they may re-receive a course completion email.
To reset progress for a course, go into the Progress section and choose the course you've added new lessons to and click on the Recalculate Completions button:
Jeff enrolls in your course when it contains 5 lessons. He completes the course, and records show he has 100% in the course.
After Jeff completes the course, you add 5 additional lessons to the course. As Jeff is already complete, he continues to show 100% completion but will show 50% viewed.
If you wish to reset Jeff's progress calculation, the Recalculate Progress in the course progress report to recalculate Jeff's completion, showing 50% completion (based on the new total lesson count) and 50% viewed.