Participation is always as a member of one group or another.
Groups join together in open ended discussions.
Discussions have decision periods with rating results by group, gender and age.
Also useful to know:
If in expert mode, you can change the group by using the menu on the left. If a group belongs to a discussion, there will be a discussion button at the top of the group page. You are encouraged to rate the messages for interest and approval. To expand a message, click the message title or the + sign.