As an instructor or teaching assistant, course materials are always visible to you. However, you can control the material you make visible to students. You can show or hide
entire folders or individual assets such as activities, links, files, or pages.
You can also control the date and time that assignments are made available to students. If you create assignments and do not set any further date or time restrictions, the material is available immediately to students for the duration of the course. For details on how to control assignment availability, see Schedule or restrict assignment availability.
Note: Teaching assistants must have permission to show/hide course materials. Instructors use the Preferences > Permissions page to determine whether teaching assistants can perform these actions.
To make assets available or unavailable to students:
Go to the Course Materials > Add Course Materials page or the Course Materials > Add from Library page.
In the My Course list, locate and confirm the current status of the asset. The asset's status appears beneath the asset. "Shown" indicates that the asset is visible to students, and "Hidden" indicates the asset is not visible to students. Hidden assets appear dimmed and in italic font.
Change the asset status:
To change the status for a single asset, select Show/Hide from the asset's options menu.
To change the status for one or more assets at once, select the assets and click Show/Hide on the list toolbar.
If the asset was previously "shown," its status is now "hidden" and the asset appears dimmed in italic font. Students cannot see hidden material.
If the asset was previously "hidden," its status is now "shown." Students can see shown material.
Note: On the Assignment Calendar page, a yellow light bulb icon indicates a shown asset and a dim light bulb icon indicates a hidden asset.
Tip: At any time, click Go to Student View in the top-right corner of the page to view what your students see.
indicates a shown asset and a dim light bulb icon 
indicates a hidden asset.