 | This is anexplanatory essay about theWikipedia:Reliable sources guideline. This page provides additional information about concepts in the page(s) it supplements. This page is not one ofWikipedia's policies or guidelines as it has not beenthoroughly vetted by the community. |
 | This page in a nutshell: Do not use a Wikipedia article as a source for another Wikipedia article. |
Wikipedia is not an acceptable source for citations elsewhere on Wikipedia. As auser-generated source, it can be edited by anyone at any time, and any information it contains at a particular time could bevandalism,a work in progress, or simply incorrect.Biographies of living persons, subjects that happen to be in the news, and politically or culturally contentious topics are especially vulnerable to these issues. Edits on Wikipedia that are in error may eventually be fixed. However, because Wikipedia is a volunteer-run project, it cannot constantly monitor every contribution. There are many errors that remain unnoticed for hours, days, weeks, months, or even years (seeWikipedia:List of hoaxes on Wikipedia). Additionally, it is possible that some errors may never be fixed. It is also possible for an edit correcting an error to later be reverted. Therefore, Wikipedia shouldnot be considered a definitive source in and of itself. This includesarticles, non-article pages,The Signpost, and non-English Wikipedias.
The same applies to Wikipedia'ssister projects, such asWiktionary andWikimedia Commons, as well as websites thatmirror oruse it as a source themselves, andprinted books or other material derived primarily or entirely from Wikipedia articles; seeWP:CIRCULAR for guidance.
Articles are only as good as theeditors who have been editing them—their interests, biases, education, and background—and the efforts they have put into a particular topic or article. Since we try to avoidoriginal research, a particular article may only be as good as (a) the available and discoveredreliable sources, and (b) the subject may allow. Since the vast majority of editors are anonymous, you have only theirediting history and theiruser pages as benchmarks. Of course, Wikipedia makes no representation as to their truth. Further, Wikipedia is collaborative by nature, and individual articles may be the work of one or many contributors over varying periods. Articles vary in quality and content, widely and unevenly, and also depending on the quality of sources (and their writers, editors, and publishers) that are referenced and/or linked. Circumstances may have changed since the edits were added.
Occasionally, inexperienced editors may unintentionally cite the Wikipedia article about a publication instead of the publication itself; in these cases, fix the citation instead of removing it. Although citing Wikipedia as a source is against policy, content can be copied between articles with proper attribution; seeWP:COPYWITHIN for instructions.