You are not asking when and why. Why? Forums have a life cycle. They start small, full of interesting people. Hoi polloi find them and join, to spectate and s

You are not asking when and why. Why? Forums have a life cycle. They start small, full of interesting people. Hoi polloi find them and join, to spectate and snark and lark. The signal to noise ratio falls and the interesting people leave. Forums self limit by drowning in mediocrity. If some mechanism could prevent this a forum could grow larger and have more interesting people on it. There may well be a critical mass of interesting people that no forum has reached yet. Failing that it would still be a big win if a forum could persist. Having to move on and find somewhere else is a pain and people would use a complicated system if it actually delivered on the promise of keeping the signal to noise ratio up. What is at issue is the individual signal to noise ration, what you see given your white list. It doesn't matter if the forum as a whole goes down the tubes as long as the interesting people never find out. It also doesn't matter if people disagree about what is signal and what is noise, each to his own white list. When? Outer Circle starts small. So participants can simply use the ALL option, and not bother with rating. However, the Outer Circle client should offer each user vote up and vote down puttons. These are private. As the forum grows and ages, two things happen: there is plenty to read, the signal to noise ration falls. Each participant has a breaking point at which he asks the system to use the his personal voting tallies to auto-build him a white list. Perhaps it should include those with positive totals and leave out those with negative totals. That could be done with putting all the positives on level zero, but if the forum is thriving the list will be thousands long. No. It is important that the auto-build takes some time to discover some structure so that it can build a hierarchical list. There is a social science hypothesis lurking here. Outer Circle assumes that the authors you rate very highly will read authors that you rate highly and that there is a clustering of preferences sufficiently tight that hierarchical sharing of white lists becomes an efficient way of constructing and managing large white lists. There after rating is pain-driven. When the signal to noise ration that you experience drops too low you think to yourself "Outer Circle is dying, where do I go to instead?" Then you remember your white list. You have continued to upvote and downvote, it is a habit, even though it doesn't seem to do anything. Now you can ask your Outer Circle client why the forum has become crap and it can tell you the paths by which you see the articles and suggest deepenings, shallowings, and directings to improve your experience. I think that there is a threshold effect. If the rating system is elaborate enough to keep the forum from dying it is worth the hassle, but a slightly simply system, which merely slows the decline and thus prolongs the agony is worthless.