Assign students to play out roles of devil's advocate, pessimist or optimist to help them take different sides and spur debate. Peer camaraderie is lacking. Assign online buddies. Pair up students to help each other troubleshoot software problems and respond to questions about course content. Instructors struggle to teach and not preach.
Instructors easily fall into lecture mode.
Encourage students to initiate discussion topics. Require them to take turns running discussion threads about readings. Because students can't see each other, it takes time for them to build trust and speak freely. Encourage students to interact casually. Create discussion threads or areas for hanging out and personal introductions.