Reihan points to Chris Wilson’s interesting Slate article on “The Myth of Web 2.0 Democracy”. In this article Wilson posits a spectrum of different Web 2.0 models for determing accuracy or truth, ranging from anarchy to dictatorship. I think the key issues are (1) the extent to which there is some absolute frame of reference for accuracy, and (2) some knowable location for this truth if it exists.
To take one extreme case, Web 2.0 social media sites that are intended to find consumer preferences, or more typically, relationships between individual preferences (such as the Amazon collaborative filtering recommendation system), clearly function better as “democracies” (although exactly how one writes the “constitution” – the specific rules and parameters by which the collaborative filtering engine operates – will hugely impact the effectiveness of the democracy, as denominated by the change in net cash flow of the site).
To take the other extreme, a Wikipedia entry on the height of Mt. Everest is subject to an objective (or at least as objective as anything in the real world ever gets) measurement. The “wisdom of crowds” stuff only gets important when you are faced with a theoretically-knowable piece of information for which no measurement exists and for which expert opinion is not believed to be a reliable guide. The shortest description for this is usually simple: a market.