MLA:
“King Arthur.” Wikipedia. 26 July 2006. <http://en.wikipedia.org/wiki/King_Arthur>.
[“page title.”] [date of access.] [<URL>]APA:
King Arthur. Wikipedia. Retrieved July 26, 2006, from: http://en.wikipedia.org/wiki/King_Arthur
[page title.] [Retrieved date, from: URL]Chicago:
26. “King Arthur.”
[fn. #.] [“title.”]
[Shortened Chicago reference; see More Notes on Chicago Style for more information.]
[Note: In the Bibliography, Chicago style does not generally include date of access.]
To list material from Wikipedia, you should review the advice for organization websites. But Wikipedia merits additional attention because of its recent growth and popularity. Some professors will warn you not to use Wikipedia because they believe its information is unreliable. As a community project with no central review committee, Wikipedia certainly contains its share of incorrect information and uninformed opinion. And since it presents itself as an encyclopedia, Wikipedia can sometimes seem more trustworthy than the average website, even to writers who would be duly careful about private websites or topic websites. In this sense, it should be treated as a popular rather than scholarly source. See Popular vs. Scholarly Sources for more information.
But the main problem with using Wikipedia as an important source in your research is not that it gets things wrong. Some of its contributors are leaders in their fields, and, besides, some print sources contain errors. The problem, instead, is that Wikipedia strives for a lower level of expertise than professors expect from Yale students. As an encyclopedia, Wikipedia is written for a common readership. But students in Yale courses are already consulting primary materials and learning from experts in the discipline. In this context, to rely on Wikipedia—even when the material is accurate—is to position your work as inexpert and immature.
If you use Wikipedia for general background, check several other sources before using the material in your essays. Some of the facts you find may be attributable to common knowledge (see Common Knowledge for more discussion). You may also be able to track opinions or deeper ideas back to their original sources. In many cases, your course readings will contain similar ideas in better, more quotable language. Many student writers are tempted to use Wikipedia for definitions of terms (the same way a beginning writer might quote a dictionary). But in most cases, a definition drawn or paraphrased from the primary course readings—or from other scholarly sources—will be more effective. See Why Cite? for more discussion of definitions and keyterms.
Of course, if you do use language or information from Wikipedia, you must cite it—to do otherwise constitutes plagiarism. The advice here is not to hide what Wikipedia contributes to your ideas, but rather to move beyond Wikipedia and write from a more knowledgeable, expert stance.
