This page in a nutshell: Wikipedia does not publish original thought. All material in Wikipedia must be attributable to a reliable, published source. Articles must not contain any new analysis or synthesis of published material that reaches or implies a conclusion not clearly stated by the sources themselves. Simple calculations are not original research, see § Routine calculations. |
Wikipedia articles must not contain original research. On Wikipedia, original research means material—such as facts, allegations, and ideas—for which no reliable, published source exists.[a] This includes any analysis or synthesis of published material that reaches or implies a conclusion not stated by the sources. To demonstrate that you are not adding original research, you must be able to cite reliable, published sources that are directly related to the topic of the article and directly support[b] the material being presented.
The prohibition against original research means that all material added to articles must be verifiable in a reliable, published source, even if not already verified via an inline citation. 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.[a] For example, the statement "the capital of France is Paris" does not require a source to be cited, nor is it original research, because it's not something you thought up and it is easily verifiable; therefore, no one is likely to object to it and we know that sources exist for it even if they are not cited. The statement is verifiable, even if not verified.
Despite the need for reliable sources, you must not plagiarize them or violate their copyrights. Rewriting source material in your own words while retaining the substance is not considered 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 No original research noticeboard.
This policy does not apply to talk pages and other pages which evaluate article content and sources, such as deletion discussions or policy noticeboards.
Using sources
Wikipedia is fundamentally built on research that has been collected and organized from reliable sources, as described in content policies such as this one. 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.
The 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 being verifiable in 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 the sources express 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.
Reliable sources
Any material 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 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 state 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:
- Peer-reviewed journals
- Books published by university presses
- University-level textbooks
- Magazines, journals, and books published by respected publishing houses
- Mainstream newspapers
However, note that higher standards than this are required for medical claims.
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. 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. Any 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. References must be cited in context and on topic.
Primary, secondary and tertiary sources
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 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. Even a given source can contain both primary and secondary source material for one particular statement. For the purposes of this policy, primary, secondary and tertiary sources are defined as follows:[c]
- 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 for the outcome of that experiment. For Wikipedia's purposes, breaking news stories are also considered to be primary sources. Historical documents such as diaries are as well.[d]
- 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.[e]
- Any interpretation of primary source material requires a reliable secondary source for that interpretation. While a primary source is generally the best source for its own contents, even over a summary of the primary source elsewhere, do not put undue weight on its contents.
- A primary source may be used on Wikipedia only 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 musician may cite discographies and track listings published by the record label, and 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.[under discussion]
- Do not add unsourced material from your personal experience, because that would make Wikipedia a primary source of that material.
- Use extra caution when handling primary sources about living people; see WP:Biographies of living persons § Avoid misuse of primary sources, which is policy.
- Policy: Unless restricted by another policy,