Wikipedia - A credible source?

Many of us look up definitions on Wikipedia. Last semester I was in a Multi-Agent Systems class; in my lab reports for the class, I often cited Wikipedia as a source for certain definition and descriptions. So it was interesting when I came across this article on College: Wikipedia Not Source for Papers . I think it should really depend on the professor or the teacher whether Wikipedia is acceptable for the particular subject matter. In my personal opinion one should not cite Wikipedia when talking about state of the art research matters, nor should one cite it in a technical document submitted at conference or journal. I see no harm in citing it in term papers for simple definitions like Condorcet Voting Methods .