Clay Shirky is speaking about pattern languages for moderation strategies. A pattern is a combination of a goal and strategy combination that's detailed enough that you can see how to build it, but not so detailed that you can't repurpose it to a different domain. This has come into vogue in the object oriented world.

Clay suggests a pattern strategy for moderating discussion. He shows a graph that has "freedom to create group communications" vs. "Annoyingness". The problem is there's a steep knee in the curve, meaning that there's a point where as soon as you get a certain level of freedom the annoyingness of the group skyrockets.

Clay uses Slashdot as an example of defending against this. Slashdot has managed to not be swamped by negative activity over the years. The basic trick is that Slashdot members defend readers from writers. He describes the karma system. The average reader never see posts rated 0 or -1. That accounts for 20% of the comments. Moderating is done by logged in users with high karma, randomly selected to moderate, who have chosen to moderate. That's a daunting chain of decisions.

Slashdot isn't easily replicated, even by using the using the actual code base. Neither the gestalt of understanding nor the actual code is sufficient, so we need a pattern.

The problem Slashdot faces is the tragedy of the commons. Each poster has a motive to hurt the commons to gain notoriety for themselves. Here's the pattern:

1. Move comments to a separate page
2. Treat readers and writers differently
3. Let users rate posts
4. Use defensive defaults

But who guards the guardians? A second pattern solves the problems that the first pattern creates:

1. Treat users and members differently
2. Measure good behavior
3. Enlist committed members
4. Judges can't post

Clay points to the Bronze Beta, a Buffy the Vampire fan site. He describes it as the simplest group blog you can imagine. It works, despite its simplicity, or maybe because of it. He makes the pattern explicit:

1. Don't have features
2. Make Comments central
3. Make login optional

This is the experimental wing of politic philosophy. As group conversation and cooperation move the the digitally mediated environment, we are encoding the methods of interaction. We need to get it right. We have a duty to get it right. Society needs us to get it right. having a language to talk about this is a place to start.