In the Teacher Dashboard, under My Classes, click view class to access your class page. In your class page, scroll down to your student roster, select the Course Progress tab, then select a course from the drop-down list and select the level you wish to start locking levels at. Once completed, you can scroll down to view your students' course progress and confirm levels have been locked. Locked levels can be identified by the lock icon. To unlock all levels in a course, select the no levels locked option in the drop-down menu.