Wikipedia (the "free online encyclopedia that anyone can edit") is having a huge impact on how a great many people gather information about the world. So, it is important for epistemologists and information scientists to ask whether people are likely to acquire knowledge as a result of having access to this information source. In other words, is Wikipedia having good epistemic consequences? After surveying the various concerns that have been raised about the reliability of Wikipedia, this article argues that the epistemic consequences of people using Wikipedia as a source of information are likely to be quite good. According to several empirical studies, the reliability of Wikipedia compares favorably to the reliability of traditional encyclopedias. Furthermore, the reliability of Wikipedia compares even more favorably to the reliability of those information sources that people would be likely to use if Wikipedia did not exist (viz., Web sites that are as freely and easily accessible as Wikipedia). In addition, Wikipedia has a number of other epistemic virtues (e.g., power, speed, and fecundity) that arguably outweigh any deficiency in terms of reliability. Even so, epistemologists and information scientists should certainly be trying to identify changes (or alternatives) to Wikipedia that will bring about even better epistemic consequences. This article suggests that to improve Wikipedia, we need to clarify what our epistemic values are and to better understand why Wikipedia works as well as it does.
