Over on Overcoming Bias there was a great post called “Evaporative cooling of group beliefs” where the author talks about how ejecting outliers moves the group’s average position towards the other extreme. At the end he draws an interesting conclusion:
My own theory of Internet moderation is that you have to be willing to exclude trolls and spam to get a conversation going. You must even be willing to exclude kindly but technically uninformed folks from technical mailing lists if you want to get any work done. A genuinely open conversation on the Internet degenerates fast. It’s the articulate trolls that you should be wary of ejecting, on this theory – they serve the hidden function of legitimizing less extreme disagreements. But you should not have so many articulate trolls that they begin arguing with each other, or begin to dominate conversations. If you have one person around who is the famous Guy Who Disagrees With Everything, anyone with a more reasonable, more moderate disagreement won’t look like the sole nail sticking out. This theory of Internet moderation may not have served me too well in practice, so take it with a grain of salt.
It’s interesting to compare this to the techniques Theresa Nielsen Hayden uses on her “Making Light” blog and on Boing Boing comments. There’s an art to building online communities that nobody has yet well documented.