Wikipedia:No original research

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Wikipedia does not publish original research or original thought. This includes unpublished facts, arguments, speculation, and ideas, as well as any unpublished analysis or synthesis of published material that serves to advance a position. This means that Wikipedia is not the place to publish your own opinions, experiences, arguments, or conclusions.

Citing sources and avoiding original research are linked. In order to show that what is stated in an article or section, reliable sources must be cited. These sources should be directly related to the topic of the article. They should also directly support the information as it is presented.

"No original research" is one of three core content policies. The others are neutral point of view and verifiability. Together, these policies determine the type and quality of material that is acceptable in articles. These three support each other and make a whole. For this reason, they should not be interpreted standing alone, but only together. Editors should familiarize themselves with all three.


Research that consists of collecting and organizing material from existing sources within the provisions of this and other content policies is encouraged: this is "source-based research", and it is fundamental to writing an encyclopedia. Take care, however, not to go beyond what is expressed in the sources or to use them in ways inconsistent with the intent of the source, such as using material out of context. In short, stick to the sources.

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

Reliable sources

Any material that is challenged or likely to be challenged must be supported by a reliable source. Material for which no reliable source can be found is considered original research. The only way you can show that your edit does not come under this category is to produce a reliable published source that contains that same material. Even with well-sourced material, however, if you use it out of context or to advance a position that is not directly and explicitly supported by the source used, you as an editor are engaging in original research; see below.

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 more people engaged in checking facts, analyzing legal issues, and scrutinizing the writing, the more reliable the publication. Material that is self-published, whether on paper or online, is generally not regarded as reliable, but see these sections of Verifiability for exceptions.

If you are able to prove something that few or none currently believe, Wikipedia is not the place to première such a proof. Once a proof has been presented in a reliable source, however, it may be referenced.

Using sources

Information in an article must be verifiable in the references cited. Article statements generally should not rely on unclear or inconsistent passages nor on passing comments. Passages open to multiple interpretations should be precisely cited or avoided. A summary of extensive discussion should reflect the conclusions of the source's author(s). Drawing conclusions not evident in the reference is original research regardless of the type of source. It is important that references be cited in context and on topic.

Primary, secondary and tertiary sources

Wikipedia articles should rely mainly on published reliable secondary sources and, to a lesser extent, on tertiary sources. All interpretive claims, analyses, or synthetic claims about primary sources must be referenced to a secondary source, rather than original analysis of the primary-source material by Wikipedia editors.

For the purposes of Wikipedia policies and guidelines, primary, secondary and tertiary sources are defined as follows:[1][2]

  • Tertiary sources are publications such as encyclopedias or other compendia that mainly summarize secondary sources. For example, Wikipedia itself is a tertiary source. Many introductory undergraduate-level textbooks may also be considered tertiary sources, to the extent that they sum up multiple secondary sources.
Our policy: Tertiary sources can be helpful in providing broad summaries of topics that involve many primary and secondary sources. But they should not be used in place of secondary sources for detailed discussion. Some tertiary sources may be more reliable than others, and within any given tertiary source, some articles may be more reliable than others. WP:Verifiability#Reliable sources describes the criteria for assessing the reliability of sources. Articles and posts on Wikipedia, or on websites that mirror its content, may not be used as sources, see Wikipedia:Verifiability#Wikipedia and sources that mirror or source information from Wikipedia.
  • Secondary sources are at least one step removed from an event. They rely for their facts and opinions on primary sources, often to make analytic, synthetic, interpretive, explanatory, or evaluative claims.[3][4][5]
Our policy: Wikipedia articles usually rely on material from secondary sources. Articles may include analytic, synthetic, interpretive, explanatory, or evaluative claims so long as they have been published by a reliable secondary source.
  • Primary sources are sources very close to an event. For example, an account of a traffic accident written by a witness is a primary source of information about the accident. Other examples include archeological artifacts; photographs; historical documents such as diaries, census results, video or transcripts of surveillance, public hearings, trials, or interviews; tabulated results of surveys or questionnaires; original philosophical works; religious scripture; published notes of laboratory and field experiments or observations written by the person(s) who conducted or observed the experiments; and artistic and fictional works such as poems, scripts, screenplays, novels, motion pictures, videos, and television programs. The key point about a primary source is that it offers an insider's view to an event, a period of history, a work of art, a political decision, and so on.[6]
Our policy: Primary sources that have been reliably published (for example, by a university press or mainstream newspaper) may be used in Wikipedia, but only with care, because it is easy to misuse them. Any interpretation of primary source material requires a reliable secondary source for that interpretation. Without a secondary source, a primary source may be used only to make descriptive claims, the accuracy of which is verifiable by a reasonable, educated person without specialist knowledge. For example, an article about a novel may cite passages from the novel to describe the plot, but any interpretation of those passages needs a secondary source. So, for instance, an article about William Shakespeare's Romeo and Juliet may contain citations from that work but statements that explain what Shakespeare meant by those words need a reliable secondary source.

Unsourced material obtained from a Wikipedian's personal experience, such as an unpublished eyewitness account, should not be added to articles. It would violate both this policy and Verifiability, and would cause Wikipedia to become a primary source for that material.

Appropriate sourcing can be a complicated issue, and these are general rules. Deciding whether primary, secondary or tertiary sources are more suitable on any given occasion is a matter of common sense and good editorial judgment, and should be discussed on article talk pages.

Synthesis of published material that advances a position

Do not put together information from multiple sources to reach a conclusion that is not stated explicitly by any of the sources.

Editors should not make the mistake of thinking that if A is published by a reliable source, and B is published by a reliable source, then A and B can be joined together in an article to reach conclusion C. This would be a synthesis of published material that advances a new position, and that constitutes original research.[7] "A and B, therefore C" is acceptable only if a reliable source has published the same argument in relation to the topic of the article.

The following example is based on an actual Wikipedia article about a dispute between two authors, here called Smith and Jones.

Smith claimed that Jones committed plagiarism by copying references from another author's book. Jones responded that it is acceptable scholarly practice to use other people's books to find new references.

Now comes the original synthesis:

If Jones did not consult the original sources, this would be contrary to the practice recommended in the Harvard Writing with Sources manual, which requires citation of the source actually consulted. The Harvard manual does not call violating this rule "plagiarism". Instead, plagiarism is defined as using a source's information, ideas, words, or structure without citing them.

The first paragraph was properly sourced. The second paragraph was original research because it expressed the editor's opinion that, given the Harvard manual's definition of plagiarism, Jones did not commit it. To make the second paragraph consistent with this policy, a reliable source would be needed that specifically comments on the Smith and Jones dispute and makes the same point about the Harvard manual and plagiarism. In other words, that precise analysis must have been published by a reliable source in relation to the topic before it can be published in Wikipedia by a contributor.

Summarizing or rephrasing source material without changing its meaning is not synthesis — it is good editing. Best practice is to write Wikipedia articles by taking material from different reliable sources on the topic and putting those claims on the page in your own words, with each claim attributable to a source that explicitly makes that claim.

Citing oneself

This policy does not prohibit editors with specialist knowledge from adding their knowledge to Wikipedia, but it does prohibit them from drawing on their personal knowledge without citing their sources. If an editor has published the results of his or her research in a reliable publication, the editor may cite that source while writing in the third person and complying with our neutrality policy. See also Wikipedia's guidelines on conflict of interest.

Original images

Because of copyright law in a number of countries, there are relatively few existing images publicly available for use in Wikipedia. Photographs, drawings and other images created by Wikipedia editors thus fill a needed role. Wikipedia editors are encouraged to take photographs or draw pictures or diagrams and upload them, releasing them under the GFDL or another free license, to illustrate articles. Original images created by a Wikipedia editor are not usually considered original research – as long as they do not illustrate or introduce unpublished ideas or arguments, the core reason behind the NOR policy.

Images that constitute original research in any way are not allowed. It is not acceptable for an editor to use photo manipulation to try to distort the facts or position being illustrated by a contributed photo. Manipulated images should be prominently noted as such. Any image that is found to have manipulation that materially affects its encyclopedic value should be posted to Wikipedia:Requests for deletion.

Image captions should also follow this policy. Great care should be taken not to introduce original research into an article when captioning images.


Where English translations of non-English material are unavailable, Wikipedia editors may supply their own. If such translations are challenged, editors should cooperate in producing one they can agree on. Copyright restrictions permitting, translations published by reliable sources are preferred over those provided by Wikipedia editors.

Routine calculations

This policy does not forbid routine calculations, such as adding numbers, converting units, or calculating a person's age, provided editors agree that the arithmetic and its application correctly reflect the information published by the sources from which it is derived.


The threshold for inclusion in Wikipedia is verifiability, not truth. This policy and the verifiability policy reinforce each other by requiring that only assertions, theories, opinions, and arguments that have already been published in a reliable source may be used in Wikipedia.

Neutral point of view

The prohibition against original research limits the extent to which editors may present their own points of view in articles. By reinforcing the importance of including verifiable research produced by others, this policy promotes the inclusion of multiple points of view. Consequently, this policy reinforces our neutrality policy. In many cases, there are multiple established views of any given topic. In such cases, no single position, no matter how well researched, is authoritative. It is not the responsibility of any one editor to research all points of view. But when incorporating research into an article, it is important that editors provide context for this point of view, by indicating how prevalent the position is, and whether it is held by a majority or minority.

The inclusion of a view that is held only by a tiny minority may constitute original research. Jimbo Wales has said of this:

  • If your viewpoint is in the majority, then it should be easy to substantiate it with reference to commonly accepted reference texts;
  • If your viewpoint is held by a significant minority, then it should be easy to name prominent adherents;
  • If your viewpoint is held by an extremely small minority, then — whether it's true or not, whether you can prove it or not — it doesn't belong in Wikipedia, except perhaps in some ancillary article. Wikipedia is not the place for original research.[8]


  1. Various professional fields treat the distinction between primary and secondary sources in differing fashions. Some fields and references also further distinguish between secondary and tertiary sources. Primary, secondary and tertiary sources are broadly defined here for the purposes of Wikipedia.
  2. This University of Maryland library page provides typical examples of primary, secondary and tertiary sources.
  3. University of California, Berkeley library defines "secondary source" as "a work that interprets or analyzes an historical event or phenomenon. It is generally at least one step removed from the event".
  4. Borough of Manhattan Community College, A. Philip Randolph Memorial Library, "Research Help:Primary vs. Secondary Sources" notes that a secondary source "analyzes and interprets primary sources", is a "second-hand account of an historical event" or "interprets creative work". It also states that a secondary source "analyzes and interprets research results" or "analyzes and interprets scientific discoveries".
  5. The National History Day website states simply that: "Secondary sources are works of synthesis and interpretation based upon primary sources and the work of other authors."
  6. Definitions of primary sources:
    • The University of Nevada, Reno Libraries define primary sources as providing "an inside view of a particular event". They offer as examples: original documents, such as autobiographies, diaries, e-mail, interviews, letters, minutes, news film footage, official records, photographs, raw research data, and speeches; creative works, such as art, drama, films, music, novels, poetry; and relics or artifacts, such as buildings, clothing, DNA, furniture, jewelry, pottery.
    • The University of California, Berkeley library offers this definition: "Primary sources enable the researcher to get as close as possible to what actually happened during an historical event or time period. Primary sources were either created during the time period being studied, or were created at a later date by a participant in the events being studied (as in the case of memoirs) and they reflect the individual viewpoint of a participant or observer."
  7. Jimmy Wales has said of synthesized historical theories: "Some who completely understand why Wikipedia ought not create novel theories of physics by citing the results of experiments and so on and synthesizing them into something new, may fail to see how the same thing applies to history." (Wales, Jimmy. "Original research", December 6, 2004)
  8. Wales, Jimmy. "WikiEN-l --A Request RE a WIKIArticle--", September 29, 2003.

Further reading