[netcan]

Overall I think its amazing that an unstructured discussion involving dozens or even hundreds of people can be possible at all. It's not possible in person.

Whatever the format (threaded, non threaded, threaded with limitations) it's going to run into some limitations. They're all imperfect and I think that which one is right depends on the number of participants and velocity of comments. This threaded format seems to work well for 10-50 participants.

Stackoverflow is different in that every "topic" has a predefined structure an hierarchy of importance: a question, answers & comments. In a way, it's not tackling the same problem as HN, reddit, forums, disquss, etc.. These are trying to allow discussion regardless of the topic & structure. They are also different in that they place high importance on being accessible to casual future readers.

Unstructured "discussions" hundreds or thousands of participants is largely a problem that twitter tackled. That's why celebrities and high profile people like it.