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Plagiarism is passing off someone else's work as your own.

Plagiarism is the incorporation of someone else's work – including their language and ideas – without providing adequate credit.[1] The University of Cambridge defines plagiarism as: "submitting as one's own work, irrespective of intent to deceive, that which derives in part or in its entirety from the work of others without due acknowledgement."[2]

Wikipedia has three core content policies, two of which make it easy to plagiarize inadvertently. No original research prohibits us from adding our own ideas to articles, and Verifiability requires that articles be based on reliable published sources. These policies mean that Wikipedians are highly vulnerable to accusations of plagiarism, because we must stick closely to sources, but not too closely. Because plagiarism can occur without an intention to deceive, concerns should focus on educating the editor and cleaning up the article.

Sources are cited using inline citations, usually in the form of a citation in a footnote (see Citing sources for how to do this).[3] In addition to this, when quoting or closely paraphrasing source material, in-text attribution is almost always required – for example: "John Smith wrote that the building looked spectacular," or "Smith (2012) wrote that ...".[4] The Manual of Style requires in-text attribution when quoting a full sentence or more.[5] Naming the author in the text allows the reader to see which words rely heavily on someone else, without having to search in the footnote. You can avoid inadvertent plagiarism by remembering these three rules of thumb:

  • INCITE: Cite your sources in the form of an inline citation after the sentence or paragraph in question.
  • INTEXT: Add in-text attribution when you copy or closely paraphrase another author's words or flow of thought, unless the material lacks creativity or originates from a free source.
  • INTEGRITY: Maintain text-source integrity by placing your inline citations so that it is clear which source supports which part of the text, or use citation bundling and explain in the footnote which source supports which point.

Note that plagiarism and copyright infringement are not the same thing.[6] Copyright infringement occurs when content is used in a way that violates a copyright holder's exclusive right. Giving credit does not mean the infringement has not occurred, so be careful not to quote so much of a non-free source that you violate the non-free content guideline.[7] Similarly, public-domain content is plagiarized if used without acknowledging the source, even though there is no copyright issue. For advice on how to avoid violating copyright on Wikipedia, see Copyright violation. For how to deal with copying material from free sources, such as public-domain sources, see below.

Plagiarism on Wikipedia

Policy shortcuts:

Forms of plagiarism

Plagiarism is passing off someone else's work as your own, whether on purpose or inadvertently. Because it can happen easily and by mistake, all editors are strongly advised to look out for it in their own writing. It can take several forms:

మూస లూపు కనబడింది: మూస:Cross

Copying from an unacknowledged source

  • Inserting a text—copied word-for-word, or with very few changes—from a source that is not acknowledged anywhere in the article, either in the body of the article, or in footnotes, the references section, or the external links section.
  • The above is the most egregious form of plagiarism, and the least likely to be accidental.

మూస లూపు కనబడింది: మూస:Cross

Copying from a source acknowledged in a poorly placed citation

  • Inserting a text—copied word-for-word, or with very few changes—then citing the source somewhere in the article, but not directly after the sentence or passage that was copied.
  • This can look as though the editor is trying to pass the text off as their own. It can happen by accident when inline citations are moved around during an edit, losing text-source integrity. It can also happen when editors rely on general references listed in a References section, without using inline citations.

మూస లూపు కనబడింది: మూస:Cross

Copying from a source acknowledged in a well-placed citation, without in-text attribution

  • Inserting a text—copied word-for-word, or with very few changes—then citing the source in an inline citation after the passage that was copied, without naming the source in the text.
  • Here the editor is not trying to pass the work off as their own, but it is still regarded as plagiarism, because the source's words were used without in-text attribution. The more of the source's words that were copied, and the more distinctive the phrasing, the more serious the violation. Adding in-text attribution ("John Smith argues ...") always avoids accusations of plagiarism, though it does not invariably avoid copyright violations. Make sure the material being copied or closely paraphrased is not too long if the work is copyrighted. A few sentences would rarely be problematic.

    Be cautious when using in-text attribution, because it can lead to other problems. For example, "According to Professor Susan Jones, human-caused increases in atmospheric carbon dioxide have led to global warming" might be a violation of NPOV, because this is the consensus of many scientists, not only a claim by Jones.

మూస లూపు కనబడింది: మూస:Cross

Summarizing an unacknowledged source in your own words

  • Summarizing a source in your own words, without citing the source in any way, may also be a form of plagiarism, as well as a violation of the Verifiability policy.
  • Summarizing a source in your own words does not in itself mean you have not plagiarized, because you are still relying heavily on the work of another writer. Credit should be given in the form of an inline citation.

Avoiding plagiarism

You can avoid plagiarism by summarizing source material in your own words, and by following the rules of thumb described above: INCITE, INTEXT, INTEGRITY. Editors should check their own work periodically to make sure inline citations and in-text attribution have not been removed, displaced, or omitted inadvertently. Editors should exercise caution, especially when handling unfamiliar articles, to ensure that the text-source relationship remains intact.

Using a source's words can take these forms:


Quotation marks and in-text attribution

  • Direct speech—copying a source's words inside quotation marks, with in-text attribution and an inline citation. For example:
  • Source (John Smith, The Times, 7 November 2010): "Cottage Cheese for Beginners is the most boring book I've ever read."
  • Edit: John Smith wrote in The Times: "Cottage Cheese for Beginners is the most boring book I've ever read."[8]


No quotation marks, in-text attribution

  • Indirect speech—copying a source's words without quotation marks; this also requires in-text attribution and an inline citation. For example:
  • John Smith wrote in The Times that Cottage Cheese for Beginners was the most boring book he had ever read.[8]
  • Note: even with in-text attribution, distinctive words or phrases may require quotation marks.


Close paraphrasing and in-text attribution

  • Close paraphrasing: Sometimes close paraphrasing is appropriate or even unavoidable. Add in-text attribution so that the reader knows you are relying on someone else's words or flow of thought.
  • John Smith wrote in The Times that Cottage Cheese for Beginners was a really boring read.[8]

Respecting copyright

Regardless of plagiarism concerns, works under copyright that are not available under a compatible free license must comply with the copyright policy and the non-free content guideline. This means they cannot be extensively copied into Wikipedia articles. Limited amounts of text can be quoted if they are clearly indicated in the article as the words of someone else, using in-text attribution, quotation marks or block quotations as appropriate, followed by an inline citation.


If the source is in another language, the contributor may be under the mistaken belief that the act of translation is a sufficient revision to eliminate concerns of plagiarism. On the contrary, whether or not the work is free, the obligation remains to give credit to authors of foreign language texts for their creative expression, information and ideas, and, if the work is unfree, direct translation is likely to be a copyright violation as well.[9][10]

What is not plagiarism

Plagiarism is not a concern where the content lacks creativity. Here are some examples where in-text attribution is generally not required, though you will still need to add an inline citation:

  • use of common expressions and idioms, including those that are common in sub-cultures such as academia;[11]
  • phrases that are the simplest and most obvious way to present information; sentences such as "John Smith was born on 2 February 1900" lack sufficient creativity to require attribution;
  • simple, non-creative lists of information, such as a list of song titles on an album, or actors appearing in a film. If creativity has gone into producing a list by selecting which facts are included, or in which order they are listed, then reproducing the list without attributing it to its source may constitute plagiarism.[12]
  • mathematical and scientific formulae that are part of the general background knowledge of a field;
  • simple logical deductions.

Addressing plagiarism

Copyright violations

If you find duplicated text, or media, consider first whether the primary problem is plagiarism, or copyright infringement. If the source is not public domain, or licensed compatibly with Wikipedia, or if you suspect that it is not, you should address it under the copyright policies.

Text plagiarism

How to find text plagiarism

There are a number of methods to detect plagiarism. Plagiarized text often demonstrates a sudden change of style and tone from an editor's usual style and may appear more advanced in grammar and vocabulary. Plagiarized material may contain unexplained acronyms or technical jargon that has been described in an earlier part of the plagiarized document. Because plagiarized material was written for other purposes, it is often slightly off topic, or un-encyclopedic in tone. An editor who plagiarizes multiple sources will appear to change writing style abruptly.

An easy way to test for plagiarism of online sources is to copy and paste passages into a search engine. Exact matches, or near matches, may be plagiarism. When running such tests, be aware that some other websites reuse content from Wikipedia. A list of identified websites which do so is maintained at Wikipedia:Mirrors and forks. It is usually possible to find the exact version in article history from which a mirror copy was made. Conversely, if the text in question was added in one large edit, and the text closely matches the external source, this is an indication of direct copying. If in doubt, double check search engine results with an experienced Wikipedian.

Another option is to utilize a plagiarism detector. Plagiarism detection systems, some of which are freely available online, exist primarily to help detect academic fraud. Some such programs and services can be found at Category:Plagiarism detectors. Wikipedia does not endorse, or recommend, any external services, so your own experience will be the guide.

It can also be useful to perform a direct comparison between cited sources and text within the article, to see if text has been plagiarized, including too-close paraphrasing of the original. Here it should be borne in mind that an occasional sentence in an article that bears a recognizable similarity to a sentence in a cited source is not generally a cause for concern. Some facts and opinions can only be expressed in so many ways, and still be the same fact, or opinion. A plagiarism concern arises when there is evidence of systematic copying of the diction of one or more sources across multiple sentences or paragraphs. In addition, if the source is not free, check to be sure that any duplicated creative expressions are marked as quotations.

Addressing the editor involved

If you find an example of plagiarism, where an editor has copied text, media, or figures, into Wikipedia without proper attribution, contact the editor responsible, point them to this guideline and ask them to add attribution. Given that attribution errors may be inadvertent, intentional plagiarism should not be presumed in the absence of strong evidence.[13] Remember that contributors may not be familiar with the concept of plagiarism. Remember to start with the assumption of good faith. It may also be helpful to refer them to Wikipedia:Verifiability, Wikipedia:Citing sources, and/or Help:Citations quick reference. Editors who have difficulties, or questions about this guidance can be referred to the Help Desk, or media copyright questions.

In addition to requesting repair of the example you found, you may wish to invite the editor to identify and repair any other instances of plagiarism they may have placed before becoming familiar with this guideline. If you find that an editor persists in plagiarizing, report the editor to the administrators' noticeboard. Be sure to include diffs that show both the plagiarism and the warnings.

Repairing text plagiarism

It may not always be feasible to contact the contributor. For example, an IP editor who placed text three years ago and has not edited since is unlikely to be available to respond to your concerns. Whether you are able to contact the contributor or not, you can also change the copied material, or provide the attribution, or source on your own. Material that is plagiarized but which does not violate copyright does not need to be removed from Wikipedia if it can be repaired. Add appropriate source information to the article or file page, wherever possible. With text, you might move unsourced material to an article's talk page until sources can be found.

Media plagiarism

How to find media plagiarism

This can begin with a commonsense question: does it seem likely that the uploader is the original source? The person who scans an image from an 1825 textbook on herbs is unlikely to be the author, even if they have claimed {{PD-self}}. Sometimes doubts may be triggered by the professional quality of media, or by the exclusivity. If you suspect plagiarism, try to locate the original source through an online search engine such as Google Image Search. Other factors to consider include the editing history of the uploader and, with images, image metadata, such as Exif and XMP.[14][15]

Frequently a person who uploads and claims credit for another's image will leave the original image metadata, or a visible or invisible digital watermark, in place. If the author information conveyed by the metadata, or watermark, contradicts the author information on the image description page, this is a sign the image requires investigation. A user's original photographs can also be expected to have similar metadata, since most people own a small number of cameras; varied metadata is suspicious. Suspicions based on metadata should be checked with other editors experienced with images and other media.

Source and licensing information

For images and other media, the correct source and licensing information must be supplied, otherwise the files run the risk of deletion. Never use {{PD-self}}, {{GFDL-self}} or {{self}} if the image is not yours. If the source requests a credit line, e.g. "NASA/JPL/MSSS", place one in the author field of {{information}}.

Copying material from free sources


For free and public-domain works, use of the {{citation-attribution}} and {{source-attribution}} templates is acceptable to acknowledge the work of others and still allow subsequent modification.

Sources under copyleft

If the external work is under a copyleft license that removes some restrictions on distributing copies and making modified versions of a work, it may be acceptable to include the text directly into a Wikipedia article providing the license is compatible with the CC-BY-SA and the terms of the license are met. (A partial table of license compatibility can be found at the Copyright FAQ). Most copyleft licenses require that author attribution is given, and, even if the license does not, the material must be attributed to avoid plagiarism. Attribution for copyleft licensed text is provided through the use of an appropriate attribution template, or similar annotation, which is usually placed in a "References section" near the bottom of the page.

Public-domain sources

Whether copyright-expired or in the public domain for other reasons, material from public-domain sources is welcome on Wikipedia, but such material must be properly attributed. Public-domain attribution notices should not be removed from an article or simply replaced with in-line citations unless it is verified that substantially all phrasing has been excised (see #What is not plagiarism). Of course citable information should not be left without cites, though the most appropriate citations should be used.

A public domain source may be summarized in the same way as it is for copyrighted material (and cited in the same way as copyrighted material), but the source's text can also be copied directly into a Wikipedia article verbatim. If the text is copied then it must be cited and attributed through the use of an appropriate attribution template, or similar annotation, which is usually placed in a "References section" near the bottom of the page (see the section "Where to place attribution" for more details).

If the external work is in the public domain, but contains an original idea, or is a primary source, then it may be necessary to alter the wording of the text (for example not including all the text from the original work, or quoting some sections, or specifically attributing to a specific source an opinion included in the text,) to meet the Wikipedia content policies of neutral point of view and Wikipedia:no original research (in particular the restrictions on the use of primary sources).

A practice preferred by some Wikipedia editors, when copying in public-domain, or free content, verbatim, is to paste in the content in one edit, with indication in the edit summary of the source of the material. If following this practice, immediately follow up with careful attribution, so that the new material can't be mistaken for your own wording.

  • Put the whole text (if small enough) in blockquotes or quotation marks.
  • For sections or whole articles, add an attribution template; if the text taken does not form the entire article, specifically mention the section requiring attribution.
  • In a way unambiguously indicating exactly what has been copied verbatim, provide an inline citation and/or add your own note in the reference section of the article.

For an example of the last, see the references section in planetary nomenclature [1], which uses a large amount of text from the Gazetteer of Planetary Nomenclature.

This practice has some advantages—for example, further changes such as modernizing language and correcting errors can be done in separate edits after the original insertion of text, allowing later editors the ability to make a clear comparison between the original source text and the current version in the article.

Copying within Wikipedia

Wikipedia's content is dually licensed under both the GFDL and CC-BY license models. Contributors continue to own copyright to their contributions, but liberally license it for reuse and modification. GFDL and CC-BY do require attribution. However, since Wikipedia's articles do not contain bylines, it is not necessary or appropriate to provide attribution on the article's face. As long as the licensing requirements for attribution are met (see the guideline for specifics), copying content (including text, images, and citations) from one Wikipedia article to another or from one language Wikipedia to another is not plagiarism.

Where to place attribution

If a Wikipedia article is constructed through summarizing reliable sources, but there is a paragraph or a few sentences copied from compatibly licensed or public-domain text which is not placed within quotations, then putting an attribution template in a footnote at the end of the sentences or paragraph is sufficient. To aid with attribution at the end of a few sentences consider using the {{citation-attribution}} template, or source specific ones such as {{DNB}}.[16] Directions for usage are provided at the templates.

If a significant proportion of the text is legally copied from another source, then attribution for compatibly licensed and public-domain text is generally provided either through the use of an appropriate attribution template, or similar annotation, placed in a "References section" near the bottom of the page.

In such cases consider adding the attribution statements at the end of the Reference section directly under a line consisting of Attribution in bold:


Place appropriate attribution template, or similar annotation here

See for examples Western Allied invasion of Germany and the Battle of Camp Hill.

See also


  1. "What Constitutes Plagiarism?", Harvard Guide to Using Sources, Harvard University, accessed 20 December 2012.
  2. "University-wide statement on plagiarism", University of Cambridge, accessed 20 December 2012.
    • For subject-specific guidelines, see "Guidance provided by Faculties and Departments", University of Cambridge, accessed 20 December 2012 (note: not all the faculties have added guidance at the time of writing, so only some of the links work).
  3. For example, Smith 2012, p. 1, or Smith, John. Name of Book. Name of Publisher, 2012, p. 1.
  4. There may be exceptions when using extensive content from free or copy-left sources, so long as proper attribution is provided in footnote or in the references section at the bottom of the page.
  5. See Wikipedia:Manual of Style#Attribution: "The author of a quote of a full sentence or more should be named; this is done in the main text and not in a footnote. However, attribution is unnecessary with quotations that are clearly from the person discussed in the article or section. When preceding a quotation with its attribution, avoid characterizing it in a biased manner."
  6. Levy, Neill A. "Tweedledum and Tweedledee: Plagiarism and Copyright", Cinahl Information Systems, 17(3.4), Fall/Winter 1998.
  7. Copyright: Fair Use: "Acknowledging the source of the copyrighted material does not substitute for obtaining permission."
  8. 8.0 8.1 8.2 Smith, John. "Boring books," The Times, 7 November 2010.
  9. United States Copyright Office. "Copyright Law of the United States of America and Related Laws Contained in Title 17 of the United States Code, Circular 92". Retrieved 2009-04-09. A "derivative work" is a work based upon one or more preexisting works, such as a translation, musical arrangement, dramatization, fictionalization, motion picture version, sound recording, art reproduction, abridgment, condensation, or any other form in which a work may be recast, transformed, or adapted.... Subject to sections 107 through 122, the owner of copyright under this title has the exclusive rights to do and to authorize any of the following:...(2) to prepare derivative works based upon the copyrighted work....
  10. Buranen, Lise (1999). Perspectives on Plagiarism and Intellectual Property in a Postmodern World. SUNY Press. p. 76. ISBN 0791440796. ... large-scale cribbing of foreign-language texts might occur during the process of translation.... The practice persists even though the most flagrant violators are eventually accused and dismissed from their posts. Unknown parameter |coauthors= ignored (|author= suggested) (help)
  11. To qualify as a "common expression or idiom", the phrase must have been used without attribution at least 2 years ago by someone other than the originator and in a reliable source, in other words one that is likely to have watchful editors and lawyers; there must be no evidence that the author(s), or publisher(s), of the unattributed use later lost, or settled out of court, a lawsuit based on the unattributed use, and that the publisher did not issue an apology, or retraction, for plagiarism relating to the unattributed use. Since it is impossible to prove completely that something does not exist, Wikipedia editors who suspect plagiarism is involved must provide reliable evidence of such a legal judgment, out-of-court settlement, apology, or retraction.
  12. This may also constitute a copyright problem; U.S. law on such lists is illustrated by the case Feist Publications v. Rural Telephone Service.
  13. Avoiding plagiarism requires familiarity with citation and paraphrasing. Contributors need to know when and how to cite sources. When paraphrasing, they need to know how much they can and should retain without following too closely on source text. They also need to remember when and where they saw something first, both in active research, while note taking, and during composition, to avoid unconscious plagiarism. See Perfect, Timothy J.; Stark, Louisa J. (2008). "Tales from the Crypt...omnesia". In John Dunlosky, Robert A. Bjork (ed.). Handbook of Metamemory and Memory. CRC Press. pp. 285–314. ISBN 0805862145. Unknown parameter |chapterurl= ignored (help); |access-date= requires |url= (help).
  14. Exif data is automatically saved by most modern digital cameras, and includes important information about the camera being used and the date/time of the picture (see File:Cannon.jpg for Exif in action).
  15. XMP is utilized by Adobe in its image manipulation programs; it tracks the history of modification and, when possible, original ownership information (see File:Redding Album Cover.jpg for XMP in action).
  16. To be used as an inline citation {{DNB}} needs the "inline=1" parameter set.

Further reading

Articles, books, and journals
Digital academic resources
External links