...with an applause meter running the whole time Good point. That said, at a crude level Karma works for telling the user what kinds of comments are expected.

...with an applause meter running the whole time Good point. That said, at a crude level Karma works for telling the user what kinds of comments are expected. I am tempted, for instance, to make funny one-liners on some HN topics. Karma makes me rethink that decision, as in: does it contribute to the discussion? The posters here seem to reward intelligent analysis, so maybe a one-liner isn't a smart move ... and so on so forth.