How can I require students to post to a Discussion before they see replies?
You can require that students post to a Discussion before the see any of the other students' replies.
Click the Add Discussion button.
Click the Publish button.
Student View Discussion
Students will see a 'Replies are only visible to those who have posted at least one reply' message when they view the Discussion topic.
Note: Sometimes students will work around this requirement by deleting their posts. You can change your course settings to keep students from deleting their posts.