In some cases, Moodle may default to showing a PDF file "embedded" in the middle of a Moodle page. This is too small for most people to read. In addition, some browsers cannot display PDF's and will just show a blank spot in the middle of the page.
To control the display, edit the file item and switch the "Display" option under the Appearance section. See below for the description of the options from the Moodle documentation. It turns out "Automatic" doesn't always do a good job. "Open" or "In pop-up" work better.
- Automatic - The best display option for the file type is selected automatically
- Embed - The file is displayed within the page below the navigation bar together with the file description and any blocks
- Force download - The user is prompted to download the file
- Open - Only the file is displayed in the browser window
- In pop-up - The file is displayed in a new browser window without menus or an address bar
- In frame - The file is displayed within a frame below the the navigation bar and file description
- New window - The file is displayed in a new browser window with menus and an address bar
The same option can be switched for URL's. The "Automatic" option defaults to showing a new Moodle page displaying the link. To let students go to the linked page directly, choose "Open" or "In pop-up."