Simson L. Garfinkel discusses the epistemology behind Wikipedia in an interesting article in Technology Review.

So what is Truth? According to Wikipedia’s entry on the subject, “the term has no single definition about which the majority of professional philosophers and scholars agree.” But in practice, Wikipedia’s standard for inclusion has become its de facto standard for truth, and since Wikipedia is the most widely read online reference on the planet, it’s the standard of truth that most people are implicitly using when they type a search term into Google or Yahoo. On Wikipedia, truth is received truth: the consensus view of a subject.

Bill Badke’s article in Online provides a helpful analysis of Wikipedia’s acceptance (or lack thereof) in academia…

But notice how very analog that is, just as much of academia remains analog and simply has not bought into the amazing power of the digital Information Age. For most academics, peer review and print publication are a mainstay. True, academia has made concessions to digital reference sources, electronic full text, and open access. But all of this is simply an electronic format for an analog world in which most of what is available as electronic full text has a counterpart print version. Even those peer-reviewed, open access, online-only journals are produced by the same principles as print production—submission to an editor, peer review, and publication in tidy volumes and issue numbers.

….

But isn’t that just the point? Wikipedia users appear to be abandoning a world of certainty for an intangible universe made up of half-blown ideas and blatant errors. The problem is, they have not abandoned anything. They have never been part of the analog generation. Wikipedia is their world, and it has met their needs wonderfully. To tell them to use only the print encyclopedias for reference information is to make them ask, “Why should I when Wikipedia is at my fingertips?” They don’t know the analog world very well, and what they see is a law of diminishing returns—too much effort for too little benefit.

I would add that it seems to be more than simply a difference between analog and digital culture. It seems to me that Wikipedia assumes a different epistimological model than does a print encyclopedia (and most of academia). Wikipedia assumes that knowledge can be gathered, developed, organized and made accessible through collaborative social networks that are not based on sources authorized by the traditional structures of expertise of academe.