LON-CAPA HelpThe default is for all posts to be displayed, and for new posts to remain marked as 'NEW' until you explicitly mark them as read.
You can set a personal preference that will apply to your display of all discussions in all courses. If you change the display settings in an individual board or resource, by using the Change link beneath the postings, those settings will override the default or a global preference you set using your Set user preferences screen. To set/change your global discussion display preferences:
Set user preferences
in the My Space group
Discussion Display.