Psychology Wiki:Verifiability

The threshold for inclusion in Wikipedia is verifiability, not truth&mdash;that is, whether readers are able to check that material added to Wikipedia has already been published by a reliable source, not whether we think it is true. Editors should provide a reliable source for quotations and for any material that is challenged or likely to be challenged, or the material may be removed.

Verifiability is one of Wikipedia's core content policies. The others are No original research and 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 familiarize themselves with all three. To discuss the reliability of particular sources, see the reliable sources noticeboard.

Burden of evidence

 * For how to write citations, see Citing sources

The burden of evidence lies with the editor who adds or restores material. All quotations and any material challenged or likely to be challenged must be attributed to a reliable, published source using an inline citation. The source cited must clearly support the information as it is presented in the article. The source should be cited clearly and precisely to enable readers to find the text that supports the article content in question. Editors should cite sources fully, providing as much publication information as possible, including page numbers when citing books.

If no reliable, third-party sources can be found for an article topic, Wikipedia should not have an article on it.

Any material lacking a reliable source may be removed, but editors might object if you remove material without giving them sufficient time to provide references, and it has always been good practice, and expected behaviour of Wikipedia editors (in line with our editing policy), to make reasonable efforts to find sources onesself that support such material, and cite them.

If you want to request a source for an unsourced statement, consider tagging a sentence by adding the fact template, a section with unreferencedsection, or the article with refimprove or unreferenced. Alternatively, you may leave a note on the talk page requesting a source, or you may move the material to the talk page.

Do not leave unsourced or poorly sourced information that may damage the reputation of living persons or organizations in articles and do not move it to the talk page (See Biographies of living persons for details of this policy). As Wikipedia founder Jimmy Wales has put it:

Reliable sources
Articles should rely on reliable, third-party published sources with a reputation for fact-checking and accuracy. Reliable sources are necessary both to substantiate material within articles and to give credit to authors and publishers in order to avoid plagiarism and copyright violations. Sources should directly support the information as it is presented in an article and should be appropriate to the claims made: exceptional claims require high-quality sources.

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 may also be used 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.

For a guideline discussing the reliability of particular types of sources, see Reliable sources (WP:RS). Because policies take precedence over guidelines, in the case of an inconsistency between this page and that one, this page has priority, and WP:RS should be updated accordingly. To discuss the reliability of specific sources, consult the Reliable sources/Noticeboard.

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. Tiny-minority views and fringe theories need not be included, except in articles devoted to them.

Reliable sources may be print-only, electronic-only or be available in both print and electronic formats.  

Self-published sources
Anyone can create a website or pay to have a book published. For this reason, self-published books, newsletters, personal websites, open wikis, blogs, knols, patents, patent applications, forum postings, and similar sources are largely not acceptable to cite in Wikipedia.

Self-published work is acceptable to use in some circumstances, with limitations. For example, material may sometimes be cited which is self-published 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. For example, a reliable self-published source on a given subject is likely to have been cited on that subject as authoritative by a reliable source.

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 work by non-experts may also be used in limited circumstances, as described below.

Articles and posts on Wikipedia, or other websites that mirror Wikipedia content, may not be used as sources.

 

Questionable sources
Just because a source is not self-published does not automatically make it reliable. Questionable sources are those with a poor reputation for fact-checking. Such sources include websites and publications that rely heavily on rumors and personal opinions, are promotional in nature, or express views that are widely acknowledged as extremist or pseudoscience. Because of this, they can be treated similarly to the way self-published sources are treated. Questionable sources should only be used as sources of information about themselves as described below. Any contentious claims the source has made about third parties should not be repeated in Wikipedia, unless those claims have also been discussed by a reliable source.



Using self-published and questionable sources as sources on themselves
Self-published or questionable sources may be used as sources of information about themselves, especially in articles about themselves, without the requirement that they be published experts in the field, so long as:


 * 1) the material used is relevant to the notability of the subject of the article;
 * 2) it is not unduly self-serving;
 * 3) it does not involve claims about third parties;
 * 4) it does not involve claims about events not directly related to the subject;
 * 5) there is no reason to doubt its authenticity;
 * 6) the article is not based primarily on such sources;
 * 7) the source in question has been mentioned specifically in relation to the article's subject by an independent, reliable source.

Non-English sources
Because this is the English Wikipedia, for the convenience of our readers, editors should use English-language sources in preference to sources in other languages, 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. Where editors translate any direct quote, they should quote the relevant portion of the original, non-English text in a footnote or in the article. Translations published by reliable sources are preferred over translations made by Wikipedia editors.

Exceptional claims require exceptional sources
Certain red flags should prompt editors to examine the sources for a given claim:
 * surprising or apparently important claims not covered by mainstream sources;
 * reports of a statement by someone that seems out of character, embarrassing, controversial, or against an interest they had previously defended;
 * claims that are contradicted by the prevailing view within the relevant community, or which would significantly alter mainstream assumptions, especially in science, medicine, history, politics, and biographies of living persons. This is especially true when proponents consider that there is a conspiracy to silence them.

Exceptional claims in Wikipedia require high-quality sources; if such sources are not available, the material should not be included. Also be sure to adhere to other policies, such as the policy for biographies of living persons and the undue weight provision of Neutral point of view.