Wikipedia:Verifiability
From Wikipedia, the free encyclopedia
 |
This page is currently protected from editing until disputes have been resolved. |
 |
This page documents an official policy on the English Wikipedia. It has wide acceptance among editors and is considered a standard that all users should follow. When editing this page, please ensure that your revision reflects consensus. When in doubt, discuss first on the talk page. |
 |
This page in a nutshell: Articles should only contain material that has been published by reliable sources. Editors adding or restoring material that has been challenged or is likely to be challenged, or quotations, must provide a reliable published source, or the material may be removed. |
| Wikipedia policy |
|---|
| Article standards |
|
Neutral point of view |
| Working with others |
The threshold for inclusion in Wikipedia is verifiability, not truth. "Verifiable" in this context means that any reader should be able to check that material added to Wikipedia has already been published by a reliable source. Editors should provide a reliable source for quotations and for any material that is challenged or is likely to be challenged, or it may be removed.
Wikipedia:Verifiability is one of Wikipedia's core content policies. The others include Wikipedia:No original research and Wikipedia:Neutral point of view. Jointly, these policies determine the type and quality of material that is acceptable in Wikipedia articles. They should not be interpreted in isolation from one another, and editors should try to familiarize themselves with all three.
Contents |
Burden of evidence
- For how to write citations, see Wikipedia:Citing sources
The burden of evidence lies with the editor who adds or restores material. Material that is challenged or likely to be challenged needs a reliable source, which should be cited in the article. Quotations should also be attributed. If an article topic has no reliable, third-party sources, Wikipedia should not have an article on it.
Any edit lacking a source may be removed, but editors may object if you remove material without giving them a chance to provide references. If you want to request a source for an unsourced statement, consider moving it to the talk page. Alternatively, you may tag the sentence by adding the {{fact}} template, or tag the article by adding {{Not verified}} or {{Unreferenced}}. Leave an invisible HTML comment, a note on the talk page, or an edit summary explaining what you have done.[1]
Be careful not to go too far on the side of not upsetting editors by leaving unsourced information in articles for too long, or at all in the case of information about living people. Jimmy Wales, founder of Wikipedia, has said of this: "I can NOT emphasize this enough. There seems to be a terrible bias among some editors that some sort of random speculative 'I heard it somewhere' pseudo information is to be tagged with a 'needs a cite' tag. Wrong. It should be removed, aggressively, unless it can be sourced. This is true of all information, but it is particularly true of negative information about living persons."[2]
Sources
Articles should rely on reliable, third-party published sources with a reputation for fact-checking and accuracy. Sources should be appropriate to the claims made: exceptional claims require exceptional sources. All articles must adhere to Wikipedia's neutrality policy, fairly representing all majority and significant-minority viewpoints that have been published by reliable sources, in rough proportion to the prominence of each view.[3]
In general, the most reliable sources are peer-reviewed journals and books published in university presses; university-level textbooks; magazines, journals, and books published by respected publishing houses; and mainstream newspapers. As a rule of thumb, the greater the degree of scrutiny involved in checking facts, analyzing legal issues, and scrutinizing the evidence and arguments of a particular work, the more reliable it is.
Academic and peer-reviewed publications are highly valued and usually the most reliable sources in areas where they are available, such as history, medicine and science. Material from reliable non-academic sources is also welcome in these areas, particularly if they are respected mainstream publications. The appropriateness of any source always depends on the context. Where there is disagreement between sources, their views should be clearly attributed in the text.
Questionable sources
Questionable sources are those with a poor reputation for fact-checking or with no editorial oversight. Questionable sources should only be used in articles about themselves. (See below.) Articles about such sources should not repeat any contentious claims the source has made about third parties, unless those claims have also been published by reliable sources.
Self-published sources (online and paper)
Anyone can create a website or pay to have a book published, then claim to be an expert in a certain field. For that reason, self-published books, personal websites, and blogs are largely not acceptable as sources.[4]
Self-published material may, in some circumstances, be acceptable when produced by an established expert on the topic of the article whose work in the relevant field has previously been published by reliable third-party publications. However, caution should be exercised when using such sources: if the information in question is really worth reporting, someone else is likely to have done so.
Self-published sources should never be used as third-party sources about living persons, even if the author is a well-known professional researcher or writer; see WP:BLP.
Self-published and questionable sources in articles about themselves
Material from self-published and questionable sources may be used as sources in articles about themselves, so long as:
- it is relevant to their notability;
- it is not contentious;
- it is not unduly self-serving;
- it does not involve claims about third parties;
- it does not involve claims about events not directly related to the subject;
- there is no reasonable doubt as to who wrote it.
Sources in languages other than English
Because this is the English Wikipedia, for the convenience of our readers, English-language sources should be used in preference to foreign-language sources, assuming the availability of an English-language source of equal quality, so that readers can easily verify that the source material has been used correctly.
Keep in mind that translations are subject to error, whether performed by a Wikipedia editor or a professional, published translator. In principle, readers should have the opportunity to verify for themselves what the original material actually said, that it was published by a credible source, and that it was translated correctly.
Therefore, when the original material is in a language other than English:
- Where sources are directly quoted, published translations are generally preferred over editors performing their own translations directly.
- Where editors use their own English translation of a non-English source as a quote in an article, there should be clear citation of the foreign-language original, so that readers can check what the original source said and the accuracy of the translation.
See also
Notes and references
- ^ See Help:Editing#Basic text formatting: "Invisible comments to editors only appear while editing the page. If you wish to make comments to the public, you should usually go on the talk page."
- ^ Jimmy Wales (2006-05-16). "Zero information is preferred to misleading or false information". WikiEN-l electronic mailing list archive. Retrieved on 2006-06-11.
- ^ Tiny-minority views and fringe theories need not be included, except in articles devoted to them.
- ^ "Blogs" in this context refers to personal and group blogs. See e.g., Wikipedia:Articles_for_deletion/The_Game_(game)_(6th_nomination) for an often-cited example deletion discussion covering this matter. Some newspapers host interactive columns that they call blogs, and these may be acceptable as sources so long as the writers are professionals and the blog is subject to the newspaper's full editorial control; that is, when it isn't really a blog. Posts left on these columns by readers may never be used as sources.
Further reading
- Jimmy Wales. "WikiEN-l insist on sources", WikiEN-l mailing list, July 19, 2006.
