There is so much great information in this keynote speech by Mike Caulfield, but I'm pulling out this bit because it's a good reminder to me about what works in my own online classroom.
Addressing belonging requires the ability to modify and customize materials. Addressing relevance requires space for students to contribute, to publish, to remix. Addressing diversity of student strengths and knowledge requires an ecosystem of many explanations, not just the “textbook” explanation. (Source)