Wikipedia:Reliable sources
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Wikipedia articles should be based on reliable, published sources, making sure that all majority and significant minority views that have appeared in those sources are covered (see Wikipedia:Neutral point of view). If no reliable sources can be found on a topic, Wikipedia should not have an article on it.
This guideline discusses the reliability of various types of sources. The policy on sourcing is Wikipedia:Verifiability, which requires inline citations for any material challenged or likely to be challenged, and for all quotations. The verifiability policy is strictly applied to all material in the mainspace—articles, lists, and sections of articles—without exception, and in particular to biographies of living persons, which states:
Contentious material about living persons (or, in some cases, recently deceased) that is unsourced or poorly sourced—whether the material is negative, positive, neutral, or just questionable—must be removed immediately and without waiting for discussion.
In the event of a contradiction between this guideline and our policies regarding sourcing and attribution, the policies take priority and editors should seek to resolve the discrepancy. Other policies relevant to sourcing are Wikipedia:No original research and Wikipedia:Biographies of living persons. For questions about the reliability of particular sources, see Wikipedia:Reliable sources/Noticeboard.
Overview
Articles should be based on reliable, independent, published sources with a reputation for fact-checking and accuracy. This means that we publish only the analysis, views, and opinions of reliable authors, and not those of Wikipedians who have read and interpreted primary source material for themselves. The following examples cover only some of the possible types of reliable sources and source reliability issues, and are not intended to be exhaustive. Proper sourcing always depends on context; common sense and editorial judgment are an indispensable part of the process.
Definition of a source
A source is where the material comes from. For example, a source could be a book or a webpage. A source can be reliable or unreliable for the material it is meant to support. Some sources, such as unpublished texts and an editor's own personal experience, are prohibited.
When editors talk about sources that are being cited on Wikipedia, they might be referring to any one of these three concepts:
- The piece of work itself (the article, book)
- The creator of the work (the writer, journalist)
- The publisher of the work (for example, Random House or Cambridge University Press)
Any of the three can affect reliability. Reliable sources may be published materials with a reliable publication process, authors who are regarded as authoritative in relation to the subject, or both. These qualifications should be demonstrable to other people.
Definition of published
Published means, for Wikipedia's purposes, any source that was made available to the public in some form. The term is most commonly associated with text materials, either in traditional printed format or online; however, audio, video, and multimedia materials that have been recorded then broadcast, distributed, or archived by a reputable party may also meet the necessary criteria to be considered reliable sources. Like text, media must be produced by a reliable source and be properly cited. Additionally, an archived copy of the media must exist. It is convenient, but by no means necessary, for the archived copy to be accessible via the Internet.
Context matters
The reliability of a source depends on context. Each source must be carefully weighed to judge whether it is reliable for the statement being made in the Wikipedia article and is an appropriate source for that content.
In general, the more people engaged in checking facts, analyzing legal issues, and scrutinizing the writing, the more reliable the publication. Information provided in passing by an otherwise reliable source that is not related to the principal topics of the publication may not be reliable; editors should cite sources focused on the topic at hand where possible. Sources should directly support (See
Age matters
Especially in scientific and academic fields, older sources may be inaccurate because new information has been brought to light, new theories proposed, or vocabulary changed. In areas like politics or fashion, laws or trends may make older claims incorrect. Be sure to check that older sources have not been superseded, especially if it is likely that new discoveries or developments have occurred in the last few years. In particular, newer sources are generally preferred in medicine.
Sometimes sources are too new to use, such as with breaking news (where later reports might be more accurate), and primary sources which purport to debunk a long-standing consensus or introduce a new discovery (in which case awaiting studies that attempt to replicate the discovery might be a good idea, or reviews that validate the methods used to make the discovery).
With regard to historical events, older reports (closer to the event, but not too close such that they are prone to the errors of breaking news) tend to have the most detail, and are less likely to have errors introduced by repeated copying and summarizing. However, newer secondary and tertiary sources may have done a better job of collecting more reports from primary sources and resolving conflicts, applying modern knowledge to correctly explain things that older sources could not have, or remaining free of bias that might affect sources written while any conflicts described were still active or strongly felt.
Sources of any age may be prone to recentism, and this needs to be balanced out by careful editing.
Some types of sources
Many Wikipedia articles rely on scholarly material. When available, academic and peer-reviewed publications, scholarly monographs, and textbooks are usually the most reliable sources. However, some scholarly material may be outdated, in competition with alternative theories, controversial within the relevant field, or largely ignored by the mainstream academic discourse because of lack of citations. Try to cite current scholarly consensus when available, recognizing that this is often absent. Reliable non-academic sources may also be used in articles about scholarly issues, particularly material from high-quality mainstream publications. Deciding which sources are appropriate depends on context. Material should be
Scholarship
- Prefer secondary sources – Articles should rely on secondary sources whenever possible. For example, a paper reviewing existing research, a review article, monograph, or textbook is often better than a primary research paper. When relying on primary sources, extreme caution is advised. Wikipedians should never interpret the content of primary sources for themselves (see Wikipedia:No original research and Wikipedia:Neutral point of view).
- Reliable scholarship – Material such as an article, book, monograph, or research paper that has been vetted by the scholarly community is regarded as reliable, where the material has been published in reputable peer-reviewed sources or by well-regarded academic presses.
- Dissertations – Completed dissertations or theses written as part of the requirements for a doctorate, and which are publicly available (most via interlibrary loan or from Proquest), can be used but care should be exercised, as they are often, in part, primary sources. Some of them will have gone through a process of academic peer reviewing, of varying levels of rigor, but some will not. If possible, use theses that have been cited in the literature; supervised by recognized specialists in the field; or reviewed by independent parties. Dissertations in progress have not been vetted and are not regarded as published and are thus not reliable sources as a rule. Some theses are later published in the form of scholarly monographs or peer reviewed articles, and, if available, these are usually preferable to the original thesis as sources. Masters dissertations and theses are considered reliable only if they can be shown to have had significant scholarly influence.
- Citation counts – One may be able to confirm that discussion of the source has entered mainstream academic discourse by checking what scholarly citations it has received in themselvesoften.
- Isolated studies – Isolated studies are usually considered tentative and may change in the light of further academic research. If the isolated study is a primary source, it should generally not be used if there are secondary sources that cover the same content. The reliability of a single study depends on the field. Avoid review articlesare preferred when available, so as to provide proper context.
- POV and peer review in journals – Care should be taken with journals that exist mainly to promote a particular point of view. A claim of peer review is not an indication that the journal is respected, or that any meaningful peer review occurs. Journals that are not peer reviewed by the wider academic community should not be considered reliable, except to show the views of the groups represented by those journals.[notes 1]
- Predatory journals – Some journals are of very low quality that have only token peer-review, if any (see self-published sources.[notes 2] If you are unsure about the quality of a journal, check that the editorial board is based in a respected accredited university, and that it is included in the relevant high-quality citation index—be wary of indexes that merely list almost all publications, and do not vet the journals they list. For medical content, more guidance is available at WP:MEDRS.
- Preprints – WP:MEDRS. However, links to such repositories can be used as open-access links for papers which have been subsequently published in acceptable literature.
News organizations
News sources often contain both factual content and opinion content. News reporting from well-established news outlets is generally considered to be reliable for statements of fact (though even the most reputable reporting sometimes contains errors). News reporting from less-established outlets is generally considered less reliable for statements of fact. Most newspapers also reprint items from news agencies such as Reuters, Interfax, Agence France-Presse, United Press International or the Associated Press, which are responsible for accuracy. The agency should be cited in addition to the newspaper that reprinted it.
Editorial commentary, analysis and
- When taking information from opinion content, the identity of the author may help determine reliability. The opinions of specialists and recognized experts are more likely to be reliable and to reflect a significant viewpoint.[notes 3] If the statement is not authoritative, attribute the opinion to the author in the text of the article and do not represent it as fact. Reviews for books, movies, art, etc. can be opinion, summary, or scholarly pieces.[7][8]
- Scholarly sources and high-quality non-scholarly sources are generally better than news reports for academic topics. Press releases from the organizations or journals are often used by newspapers with minimal change; such sources are churnalism and should not be treated differently than the underlying press release. Occasionally, some newspapers still have specialist reporters who are citable by name. With regard to biomedical articles, see also Wikipedia:Identifying reliable sources (medicine).
- The reporting of rumors has a limited encyclopedic value, although in some instances verifiable information about rumors may be appropriate (i.e. if the rumors themselves are noteworthy, regardless of whether or not they are true). .
- Some news organizations have used Wikipedia articles as a source for their work. Editors should therefore beware of circular sourcing.[notes 4]
- Whether a specific news story is reliable for a fact or statement should be examined on a case-by-case basis.
- Multiple sources should not be asserted for any wire service article. Such sources are essentially a single source.
- Some news organizations do not publish their editorial policies.
- Signals that a news organization engages in fact-checking and has a reputation for accuracy are the publication of corrections and disclosures of conflicts of interest.
Vendor and e-commerce sources
Although the content guidelines for
Rankings proposed by vendors (such as bestseller lists at Amazon) usually have at least one of the following problems:
- It may be impossible to provide a stable source for the alleged ranking.
- When only self-published by the vendor, i.e. no reliable independent source confirming the ranking as being relevant, the ranking would usually carry insufficient weight to be mentioned in any article.
For such reasons, such rankings are usually avoided as Wikipedia content.
Biased or opinionated sources
Wikipedia articles are required to present a neutral point of view. However, reliable sources are not required to be neutral, unbiased, or objective. Sometimes non-neutral sources are the best possible sources for supporting information about the different viewpoints held on a subject.
Common sources of bias include political, financial, religious, philosophical, or other beliefs. Although a source may be biased, it may be reliable in the specific
Questionable and self-published sources
Questionable sources
Questionable sources are those with a poor reputation for checking the facts or with no editorial oversight. Such sources include websites and publications expressing views that are widely acknowledged as extremist, that are promotional in nature, or that rely heavily on rumors and personal opinions.[9] Questionable sources are generally unsuitable for citing contentious claims about third parties, which includes claims against institutions, persons living or dead, as well as more ill-defined entities. The proper uses of a questionable source are very limited.
Beware of sources that sound reliable but do not have the
Sponsored content
Sponsored content is generally unacceptable as a source, because it is paid for by advertisers and bypasses the publication's editorial process. Reliable publications clearly indicate sponsored articles in the byline or with a disclaimer at the top of the article. Sources that do not clearly distinguish staff-written articles from sponsored content are also questionable.
Symposia and supplements to academic journals are often (but far from always) unacceptable sources. They are commonly sponsored by industry groups with a financial interest in the outcome of the research reported. They may lack independent editorial oversight and peer review, with no supervision of content by the parent journal.[13] Such articles do not share the reliability of their parent journal,[14] being essentially paid ads disguised as academic articles. Such supplements, and those that do not clearly declare their editorial policy and conflicts of interest, should not be cited.
Indications that an article was published in a supplement may be fairly subtle; for instance, a letter "S" added to a page number,
Self-published sources (online and paper)
Anyone can create a
User-generated content
Content from websites whose content is largely user-generated is generally unacceptable. Sites with user-generated content include personal websites, personal and group blogs (excluding newspaper and magazine blogs), content farms, Internet forums, social media sites, fansites, video and image hosting services, most wikis and other collaboratively created websites.
Examples of unacceptable user-generated sources are
(self referencing). For official accounts from celebrities and organizations on social media, see the section about self-published sources below.Although review aggregators (such as Rotten Tomatoes and Metacritic) may be reliable when summarizing experts, the ratings and opinions of their users are not.
In particular, a wikilink is not a reliable source.
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 the following criteria are met:
- The material is neither unduly self-serving nor an exceptional claim.
- It does not involve claims about third parties (such as people, organizations, or other entities).
- It does not involve claims about events not directly related to the subject.
- There is no reasonable doubt as to its authenticity.
- The Wikipedia article is not based primarily on such sources.
These requirements also apply to pages from social networking websites such as Twitter, Tumblr, and Facebook. Use of self-sourced material should be de minimis; the great majority of any article must be drawn from independent sources.
Reliability in specific contexts
Biographies of living persons
Editors must take particular care when writing biographical material about living persons. Contentious material about a living person that is unsourced or poorly sourced should be removed immediately; do not move it to the talk page. This applies to any material related to living persons on any page in any namespace, not just article space.
Primary, secondary, and tertiary sources
Wikipedia articles should be based mainly on reliable
Reputable
When editing articles in which the use of primary sources is a concern, in-line templates, such as {{
Medical claims
Ideal sources for biomedical assertions include general or systematic reviews in reliable, independent, published sources, such as reputable medical journals, widely recognised standard textbooks written by experts in a field, or medical guidelines and position statements from nationally or internationally reputable expert bodies. It is vital that the biomedical information in all types of articles be based on reliable, independent, published sources and accurately reflect current medical knowledge.
Quotations
The accuracy of quoted material is paramount and the accuracy of quotations from living persons is especially sensitive. To ensure accuracy, the text of quoted material is best taken from (and cited to) the original source being quoted. If this is not possible, then the text may be taken from a reliable secondary source (ideally one that includes a citation to the original). No matter where you take the quoted text from, it is important to
Partisan secondary sources should be viewed with suspicion as they may misquote or quote out of context. In such cases, look for neutral corroboration from another source.
Any analysis or interpretation of the quoted material, however, should rely on a secondary source (see Wikipedia:No original research).
Academic consensus
A statement that all or most scientists or scholars hold a certain view requires reliable sourcing that directly says that all or most scientists or scholars hold that view. Otherwise, individual opinions should be identified as those of particular, named sources. Editors should avoid original research especially with regard to making blanket statements based on
Usage by other sources
How accepted and high-quality reliable sources use a given source provides evidence, positive or negative, for its reliability and reputation. The more widespread and consistent this use is, the stronger the evidence. For example, widespread citation without comment for facts is evidence of a source's reputation and reliability for similar facts, whereas widespread doubts about reliability weigh against it. If outside citation is the main indicator of reliability, particular care should be taken to adhere to other guidelines and policies, and to not represent unduly contentious or minority claims. The goal is to reflect established views of sources as far as we can determine them.
Statements of opinion
Some sources may be considered reliable for statements as to their author's opinion, but not for statements asserted as fact. For example, an inline qualifier might say "[Author XYZ] says....". A prime example of this is opinion pieces in mainstream newspapers. When using them, it is best to clearly attribute the opinions in the text to the author and make it clear to the readers that they are reading an opinion.
Otherwise reliable news sources—for example, the website of a major news organization—that publish in a blog-style format for some or all of their content may be as reliable as if published in standard news article format.
There is an important exception to sourcing statements of fact or opinion: Never use self-published books, zines, websites, webforums, blogs and tweets as a source for material about a living person, unless written or published by the subject of the biographical material. "Self-published blogs" in this context refers to personal and group blogs; see Wikipedia:Biographies of living persons § Reliable sources and Wikipedia:Biographies of living persons § Using the subject as a self-published source.
The exception for statements ABOUTSELF is covered at Wikipedia:Verifiability#Self-published or questionable sources as sources on themselves.
Breaking news
Breaking-news reports often contain serious inaccuracies. As an electronic publication, Wikipedia can and should be up to date, but
When editing a current-event article, keep in mind the tendency towards recentism bias. Claims sourced to initial news reports should be immediately replaced with better-researched and verified sources as soon as such articles are published, especially if original reports contained inaccuracies. All breaking news stories, without exception, are primary sources, and must be treated with caution: see Wikipedia:No original research § Primary, secondary and tertiary sources, Wikipedia:Identifying and using primary sources § Examples of news reports as primary sources.
The {{
For health- and science-related breaking-news, Wikipedia has specific sourcing standards to prevent inaccuracies: see awaiting FDA approval
" or in pre-clinical testing" as more than 90% of all treatments fail during these stages and,[19] even if efficacious, may be 10 to 15 years or more from reaching the consumer market.[20]
Headlines
News
Deprecated sources
A small number of sources are deprecated on Wikipedia. That means they should not be used, unless there is a specific consensus to do so. Deprecation happens through a
A deprecated source should not be used to support factual claims. While there are exceptions for
Some sources are blacklisted, and can not be used at all. Blacklisting is generally reserved for sources which are added abusively, such as state-sponsored fake news sites with a history of addition by
See also
Templates
- {{independent of the topic and provide significant coverage of it beyond a mere trivial mention. If notability cannot be shown, the article is likely to be merged, redirected, or deleted.)
Find sources: "Reliable sources" – news · newspapers · books · scholar · JSTOR
Policies and guidelines
Information pages
Locating reliable sources
- Free English newspaper sources
- Reliable sources/Perennial sources, a list of frequently discussed sources
- List of academic databases and search engines
- List of digital library projects
- List of online newspaper archives
- The Wikipedia Library, a program for accessing paywalled resources free of charge
- WikiProject Resource Exchange/Shared Resources
- WikiProject Resource Exchange/Resource Request
Essays
- Articles on sources
- Applying reliability guidelines
- Cherrypicking
- Children's, adult new reader, and large print sources
- Dictionaries as sources
- Don't "teach the controversy" (phrase doesn't mean what you think it does)
- Frequently misinterpreted sourcing policy
- Identifying reliable sources (history)
- Identifying reliable sources (law)
- Identifying reliable sources (science)
- Identifying and using tertiary sources
- Identifying and using style guides
- NPOV means neutral editing, not neutral content
- Wikipedia:Otto Middleton (or why newspapers are dubious sources)
- Reliable source examples
- Reliable sources checklist (provides a ref-vetting method)
- Potentially unreliable sources
- Tertiary-source fallacy
- Vanity and predatory publishing
- Wikipedia clones
Other
- Change detection and notification
- Current science and technology sources
- News sources
- Reliable sources/Noticeboard – obtain community input on whether or not a source meets our reliability standards for a particular use
- Reliable sources quiz
- Source criticism
- Wikipedia Signpost/2008-06-26/Dispatches – Signpost article
- WikiProject Reliability
Notes
- ^ Examples include The Creation Research Society Quarterly and Journal of Frontier Science (the latter uses blog comments as peer review). Archived 2019-04-20 at the Wayback Machine).
- ^ Many submissions to these predatory journals will be by scholars that a) cannot get their theories published in legitimate journals, b) were looking to quickly publish something to boost their academic resumes, or c) were honestly looking for a legitimate peer-review process to validate new ideas, but were denied the feedback by fraudulent publishers.
- ^ Please keep in mind that any exceptional claim would require exceptional sources, and this is policy.
- ^ A variety of these incidents have been documented by Private Eye and others and discussed on Wikipedia, where incorrect details from articles added as vandalism or otherwise have appeared in newspapers
References
- ^ Beall, Jeffrey (1 January 2015). "Criteria for Determining Predatory Open-Access Publishers" (PDF) (3rd ed.). Scholarly Open Access. Archived from the original on 5 January 2017.
- ^ Kolata, Gina (April 7, 2013). "Scientific Articles Accepted (Personal Checks, Too)". The New York Times. Archived from the original on April 11, 2013. Retrieved April 11, 2013.
- from the original on April 13, 2013. Retrieved April 11, 2013.
- PMID 24092725.
- ^ Kolata, Gina (30 October 2017). "Many Academics Are Eager to Publish in Worthless Journals". The New York Times. Archived from the original on 8 November 2017. Retrieved 2 November 2017.
- Salon. Salon Media Group. Archivedfrom the original on October 16, 2011. Retrieved October 17, 2011.
[Debbie Nathan] also documents a connection between Schreiber and Terry Morris, a 'pioneer' of this [human interest] genre who freely admitted to taking 'considerable license with the facts that are given to me.'
- ^ "Book reviews". Scholarly definition document. Princeton. 2011. Archived from the original on November 5, 2011. Retrieved September 22, 2011.
- ^ "Book reviews". Scholarly definition document. Virginia Polytechnic Institute and State University. 2011. Archived from the original on September 10, 2011. Retrieved September 22, 2011.
- ^ Malone Kircher, Madison (November 15, 2016). "Fake Facebook news sites to avoid". New York Magazine. Archived from the original on November 16, 2016. Retrieved November 15, 2016.
- ^ An example is the Daily Mail, which is broadly considered a questionable and prohibited source, per this RfC.
- ^ Beall, Jeffrey (25 February 2015). "'Predatory' Open-Access Scholarly Publishers" (PDF). The Charleston Advisor. Archived (PDF) from the original on 4 March 2016. Retrieved 7 January 2016.
- ^ Beall, Jeffrey. "Potential, possible, or probable predatory scholarly open-access publishers". Archived from the original on 17 January 2017.
- ^ Fees, F. (2016), Recommendations for the conduct, reporting, editing, and publication of scholarly work in medical journals (PDF), archived (PDF) from the original on 2014-03-05, retrieved 2019-01-12 Conflicts-of-interest section Archived 2018-12-30 at the Wayback Machine, [Last update on 2015 Dec].
- PMID 8015117.
- (PDF) from the original on 17 November 2018. Retrieved 12 January 2019.
- ^ See this discussion of how to identify shill academic articles cited in Wikipedia.
- ^ "The Breaking News Consumer's Handbook | On the Media". WNYC. Archived from the original on 2019-02-28. Retrieved 2019-03-14.
- ^ Gladstone, Brooke (25 December 2015). "Breaking News Consumer's Handbook: Health News Edition | On the Media". WNYC Studios. WNYC. Retrieved 23 November 2022.
- PMID 35865092.
- ^ "How long a new drug takes to go through clinical trials". Cancer Research UK. 21 October 2014. Retrieved 23 November 2022.
External links
- How to Read a Primary Source, Reading, Writing, and Researching for History: A Guide for College Students, Patrick Rael, 2004. (Also pdf version)
- How to Read a Secondary Source, Reading, Writing, and Researching for History: A Guide for College Students, Patrick Rael, 2004. (Also pdf version)
- Citogenesis (Where citations come from), xkcd comic by Randall Munroe
- "How I used lies about a cartoon to prove history is meaningless on the internet", Geek.com. How a troll used user-generated content to spread misinformation to TV.com, the IMDb, and Wikipedia.
- How to Read a News Story About an Investigation: Eight Tips on Who Is Saying What, Benjamin Wittes, Lawfare