This page in a nutshell: Wikipedia does not publish original thought. All material in Wikipedia must be attributable to a reliable, published source. Articles may not contain any new analysis or synthesis of published material that serves to reach or imply a conclusion not clearly stated by the sources themselves.
Outside of Wikipedia, original research is a key part of scholarly work. However, Wikipedia editors must not base their contributions on their own original research. Wikipedia editors must base their contributions on reliable, published sources.
Wikipedia articles must not contain original research. The phrase "original research" (OR) is used on Wikipedia to refer to material—such as facts, allegations, and ideas—for which no reliable, published sources exist.[a] This includes any analysis or synthesis of published material that serves to reach or imply a conclusion not stated by the sources. To demonstrate that you are not adding OR, you must be able to cite reliable, published sources that are directly related to the topic of the article, and directly support the material being presented. (This policy of no original research does not apply to talk pages and other pages which evaluate article content and sources, such as deletion discussions or policy noticeboards.)
The prohibition against OR means that all material added to articles must be attributable to a reliable, published source, even if not actually attributed.[a] The verifiability policy says that an inline citation to a reliable source must be provided for all quotations, and for anything challenged or likely to be challenged—but a source must exist even for material that is never challenged. For example: the statement "the capital of France is Paris" needs no source, because it is so easily verifiable that no one is likely to object to it; we know that sources exist for it even if they are not cited. The statement is attributable, even if not attributed.
Despite the need to attribute content to reliable sources, you must not plagiarize them or violate their copyrights. Rewriting source material in your own words, while substantially retaining the meaning of the references, is not considered to be original research.
"No original research" (NOR) is one of three core content policies that, along with Neutral point of view and Verifiability, determines the type and quality of material acceptable in articles. Because these policies work in harmony, they should not be interpreted in isolation from one another, and editors should familiarize themselves with all three. For questions about whether any particular edit constitutes original research, see the NOR noticeboard.
Research that consists of collecting and organizing material from existing sources within the provisions of this and other content policies is fundamental to writing an encyclopedia. Best practice is to research the most reliable sources on the topic and summarize what they say in your own words, with each statement in the article attributable to a source that makes that statement explicitly. Source material should be carefully summarized or rephrased without changing its meaning or implication. Take care not to go beyond what is expressed in the sources, or to use them in ways inconsistent with the intention of the source, such as using material out of context. In short, stick to the sources.
If no reliable independent sources can be found on a topic, Wikipedia should not have an article about it. If you discover something new, Wikipedia is not the place to announce such a discovery.
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 your edit is not original research is to cite a reliable published source that contains the same material. Even with well-sourced material, if you use it out of context, or to reach or imply a conclusion not directly and explicitly supported by the source, you are engaging in original research; see below.
In general, the most reliable sources are:
Books published by university presses
Magazines, journals, and books published by respected publishing houses
As a rule of thumb, the more people engaged in checking facts, analyzing legal issues, and scrutinizing the writing, the more reliable the publication. Self-published material, whether on paper or online, is generally not regarded as reliable, but see self-published sources for exceptions.
Information in an article must be verifiable in the references cited. In general, article statements should not rely on unclear or inconsistent passages, or 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. 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.
Wikipedia articles should be based on reliable, published secondary sources and, to a lesser extent, on tertiary sources and primary sources. Secondary or tertiary sources are needed to establish the topic's notability and to avoid novel interpretations of primary sources. All analyses and interpretive or synthetic claims about primary sources must be referenced to a secondary or tertiary source, and must not be an original analysis of the primary-source material by Wikipedia editors.
Appropriate sourcing can be a complicated issue, and these are general rules. Deciding whether primary, secondary or tertiary sources are appropriate in any given instance is a matter of good editorial judgment and common sense, and should be discussed on article talk pages. A source may be considered primary for one statement but secondary for a different one, and sources can contain both primary and secondary source material for the same statement. For the purposes of this policy, primary, secondary and tertiary sources are defined as follows:[b]
Primary sources are original materials that are close to an event, and are often accounts written by people who are directly involved. They offer an insider's view of an event, a period of history, a work of art, a political decision, and so on. Primary sources may or may not be independent sources. An account of a traffic incident written by a witness is a primary source of information about the event; similarly, a scientific paper documenting a new experiment conducted by the author is a primary source on the outcome of that experiment. Historical documents such as diaries are primary sources.[c]
Policy: Unless restricted by another policy, primary sources that have been reputably published may be used in Wikipedia, but only with care, because it is easy to misuse them.[d] Any interpretation of primary source material requires a reliable secondary source for that interpretation. A primary source may only be used on Wikipedia to make straightforward, descriptive statements of facts that can be verified by any educated person with access to the primary source but without further, specialized knowledge. For example, an article about a novel may cite passages to describe the plot, but any interpretation needs a secondary source.
Do not analyze, evaluate, interpret, or synthesize material found in a primary source yourself; instead, refer to reliable secondary sources that do so.
Do not base an entire article on primary sources, and be cautious about basing large passages on them.
A secondary source provides an author's own thinking based on primary sources, generally at least one step removed from an event. It contains an author's analysis, evaluation, interpretation, or synthesis of the facts, evidence, concepts, and ideas taken from primary sources. Secondary sources are not necessarily independent sources. They rely on primary sources for their material, making analytic or evaluative claims about them.[e] For example, a review article that analyzes research papers in a field is a secondary source for the research.[f] Whether a source is primary or secondary depends on context. A book by a military historian about the Second World War might be a secondary source about the war, but where it includes details of the author's own war experiences, it would be a primary source about those experiences. A book review too can be an opinion, summary or scholarly review.[g]
Policy: Wikipedia articles usually rely on material from reliable secondary sources. Articles may make an analytic, evaluative, interpretive, or synthetic claim only if that has been published by a reliable secondary source.
Tertiary sources are publications such as encyclopedias and other compendia that summarize primary and secondary sources. Wikipedia is a tertiary source.[h] Many introductory undergraduate-level textbooks are regarded as tertiary sources because they sum up multiple secondary sources.
Policy: Reliable tertiary sources can be helpful in providing broad summaries of topics that involve many primary and secondary sources, and may be helpful in evaluating due weight, especially when primary or secondary sources contradict each other. Some tertiary sources are more reliable than others, and within any given tertiary source, some entries may be more reliable than others. Wikipedia articles may not be used as tertiary sources in other Wikipedia articles, but are sometimes used as primary sources in articles about Wikipedia itself (see Category:Wikipedia and Category:WikiProject Wikipedia articles).
Do not combine material from multiple sources to reach or imply a conclusion not explicitly stated by any of the sources. Similarly, do not combine different parts of one source to reach or imply a conclusion not explicitly stated by the source. If one reliable source says A, and another reliable source says B, do not join A and B together to imply a conclusion C that is not mentioned by either of the sources. This would be improper editorial synthesis of published material to imply a new conclusion, which is original research performed by an editor here.[i] "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. If a single source says "A" in one context, and "B" in another, without connecting them, and does not provide an argument of "therefore C", then "therefore C" cannot be used in any article.
Here are two sentences showing simple examples of improper editorial synthesis. In the first sentence, both parts of the sentence may be reliably sourced, but they have been combined to imply that the UN has failed to maintain world peace. If no reliable source has combined the material in this way, it is original research.
NThe United Nations' stated objective is to maintain international peace and security, but since its creation there have been 160 wars throughout the world.
In this second sentence, the opposite is implied using the same material, illustrating how easily material can be manipulated when the sources are not adhered to:
NThe United Nations' stated objective is to maintain international peace and security, and since its creation there have been only 160 wars throughout the world.
Here are two paragraphs showing more complex examples of editorial synthesis. They are based on an actual Wikipedia article about a dispute between two authors, here called Smith and Jones. This first paragraph is fine, because each of the sentences is carefully sourced, using a source that refers to the same dispute:
YSmith stated 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.
This second paragraph demonstrates improper editorial synthesis:
NIf 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 second paragraph is original research because it expresses a Wikipedia 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 on Wikipedia.
Because of copyright laws in a number of countries, there are relatively few images available for use on Wikipedia. Editors are therefore encouraged to upload their own images, releasing them under appropriate Creative Commonslicenses, or other free licenses. Original images created by a Wikipedian are not considered original research, so long as they do not illustrate or introduce unpublished ideas or arguments, the core reason behind the NOR policy. Image captions are subject to this policy no less than statements in the body of the article.
It is not acceptable for an editor to use photo manipulation to distort the facts or position illustrated by an image. Manipulated images should be prominently noted as such. Any manipulated image where the encyclopedic value is materially affected should be posted to Wikipedia:Files for discussion. Images of living persons must not present the subject in a false or disparaging light.
Faithfully translating sourced material into English, or transcribing spoken words from audio or video sources, is not considered original research. For information on how to handle sources that require translation, see WP:Verifiability § Non-English sources.
Routine calculations do not count as original research, provided there is consensus among editors that the result of the calculation is obvious, correct, and a meaningful reflection of the sources. Basic arithmetic, such as adding numbers, converting units, or calculating a person's age are some examples of routine calculations. See also Category:Conversion templates.
Wikipedia's content is determined by previously published information rather than by the personal beliefs or experiences of its editors. Even if you're sure something is true, it must be verifiable before you can add it. The policy says that all material challenged or likely to be challenged, and all quotations, needs a reliable source; what counts as a reliable source is described at WP:Verifiability § Reliable sources.
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.
^ abBy "exists", the community means that the reliable source must have been published and still exist—somewhere in the world, in any language, whether or not it is reachable online—even if no source is currently named in the article. Articles that currently name zero references of any type may be fully compliant with this policy—so long as there is a reasonable expectation that every bit of material is supported by a published, reliable source.
^The University of Maryland Library provides typical examples of primary, secondary and tertiary sources.
Further examples of primary sources include archeological artifacts, census results, video or transcripts of surveillance, public hearings, investigative reports, trial/litigation in any country (including material – which relates to either the trial or to any of the parties involved in the trial – published/authored by any involved party, before, during or after the trial), editorials, columns, blogs, opinion pieces, or (depending on context) interviews; tabulated results of surveys or questionnaires; original philosophical works; religious scripture; ancient works, even if they cite earlier lost writings; tomb plaques; and artistic and fictional works such as poems, scripts, screenplays, novels, motion pictures, videos and television programs. For 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, and pottery.
The University of California, Berkeley library offers this definition: "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). They reflect the individual viewpoint of a participant or observer. Primary sources enable the researcher to get as close as possible to what actually happened during an historical event or time period".
Duke University Libraries offers this definition: "A primary source is a first-hand account of an event. Primary sources may include newspaper articles, letters, diaries, interviews, laws, reports of government commissions, and many other types of documents."
^The 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".
^The Ithaca College Library's page on primary and secondary sources compares research articles to review articles. Be aware that either type of article can be both a primary and secondary source, although research articles tend to be more useful as primary sources and review articles as secondary sources.
^Book reviews may be found listed under separate sections within a news source or might be embedded within larger news reports. Multiple coverage in book reviews is considered one of the notability criteria for books; book reviews should be considered as supporting sources in articles about books. Avoid using book reviews as reliable sources for the topics covered in the book; a book review is intended to be an independent review of the book, the author and related writing issues than be considered a secondary source for the topics covered within the book. For definitions of book reviews:
Princeton's Wordnet 2011 defines book review as "a critical review of a book (usually, [of] a recently published book)".
Virginia Tech University Libraries provides the following definition: "A book review is an article that is published in a newspaper, magazine or scholarly work that describes and evaluates a book... Reviews differ from literary critiques of books. Critiques explore the style and themes used by an author or genre."
^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".