Each Module linked to a Class has a dedicated 'Class' Discussion Channel.
The Class Channel works like any other Discussion Channel but it comes with the convenience of having a direct link to and from the Module Content page, and all the students registered for that class are automatically added to the members list.
The other two special features of the Class Channel are that student notifications are enabled by default (students get a notification every time there is a new post or comment) and that the Channel will automatically change to read-only at the end of the Term.
In other words, the Class channel saves Tutors from all the admin work of having to manually add students, explain how to find the channel, ask them to turn on notifications, and then retire the channel when it's no longer required and monitored.
From here on, all the usual features apply: additional channel members can be added by the Main Tutor or any Administrator, the Main Tutor and Admins have the power to delete and restore anyone's posts and comments, and they can also choose to retire or restore the channel manually at any time if necessary.
The point of the Class Channel is to have the kind of conversations that normally would take place in a classroom, and continue this conversations between lectures.
The Class Channel is the best place to distribute single-use learning resources*; students can react and comment immediately, and Tutors do not have the restrictions that apply to editing the 'official' content.
Students can post questions or simply share articles, music, videos to get some feedback from their peers. Tutors should nudge and encourage students to answer and help each other, simply monitoring the conversation from time to time to comment and moderate as needed.
*single-use resources: anything that is relevant to this group of students but is unlikely to be used again for years to come.
A healthy Class Channel will generate a very long thread over the course of a Term.
It will be tempting to go and create a separate Channel dedicated to the 'topic of the week' to focus the conversation on that topic and make it easier to find.
In reality, the same result can be achieved simply by tagging the channel posts.
Adding tags doesn't break the flow of the channel, while at the same time making it incredibly easy to filter out any content that doesn't match that tag.
The problem with having multiple channels (or forums, or discussion boards) is that they dilute the engagement, requiring students and tutors to go and check each one for activity.
Making Channels limited to the content of a particular lecture, is also detrimental to the idea of social learning, where the best engagement and learning opportunities are created by those water-cooler moments where people feel comfortable talking about anything and everything.