This post by jill/txt explains why she is renewing her strict efforts in disallowing the use of wiki citations in student work. I still believe that wikis are a good teaching tool and should be evaluated but should not be cited as accurate sources. They are part of the more informal information network available on the internet and should be viewed as such. It's very similar to "someone told me that" - it may be true and it may not. It's also an excellent way to assist students in developing their critical thinking skills.