Use asynchronous discussions for important, key, concepts because of the different schedules and time zones of the students. Synchronous discussions, chats, should be limited to an individual or small work group within the class.
In the classroom you have nonverbal communication but online you don't. you have only the written word unless posting a video, even then there are subtleties that may not be transferred to the audience. Read and reread posts before you click send.
