Wikipedia:Wikipedia is not a reliable source
This is an explanatory supplement to the Wikipedia:Identifying reliable sources guideline.
|This page in a nutshell: Do not use a Wikipedia article as a source for another Wikipedia article, even when describing Wikipedia.|
Wikipedia is not a reliable source. Wikipedia can be edited by anyone at any time. This means that any information it contains at any particular time could be vandalism. Biographies of living persons are especially vulnerable to this issue. Some edits on Wikipedia that are in error are sometimes fixed, however because Wikipedia cannot monitor contributions made by millions of users, there are many errors that remain unnoticed for days, weeks, months, and even years. Therefore, Wikipedia should not be considered a source for 'fact-checking'.
- Wikipedia generally uses reliable secondary sources, which vet data from primary sources. If the information on another Wikipedia page (which you want to cite as the source) has a primary or secondary source, you should be able to cite that primary or secondary source and eliminate the middleman (or "middle-page" in this case).
- Always be careful of what you read: it might not be consistently accurate.
- Neither articles on Wikipedia nor websites that mirror Wikipedia can be used as sources, because this is circular sourcing.
- An exception to this is when Wikipedia is being discussed in an article, which may cite an article, guideline, discussion, statistic or other content from Wikipedia or a sister project as a primary source to support a statement about Wikipedia (while avoiding undue emphasis on Wikipedia's role or views, and inappropriate self-reference).
- Wikipedia:Wikipedia is a tertiary source
- Wikipedia:Manual of Style/Self-references to avoid
- Wikipedia:Verifiability#Wikipedia and sources that mirror or use it
- Wikipedia:Identifying reliable sources
- Wikipedia:Wikipedia is not a publisher of original thought
- Wikipedia:Wikipedia is wrong
- Does Wikipedia Suck? on teaching students to evaluate sources