4. Forms of plagiarism

Definition of plagiarism

We can find many definitions of plagiarism in academic literature. Some consider plagiarism as theft, and accordingly these mainly emphasise the use of another person’s work. Other definitions presume intention, or they define the extent of the reused content to trigger the term plagiarism.

Norm ČSN ISO 5127 defines plagiary as “presentation of an intellectual work of another author, in whole or in part, as one’s own.”3 Plagiarism is even more precisely defined by the Czech Terminology Database of Library and Information Sciences (TDKIV) as “unauthorised imitation (exact or partial) of an artistic or scientific work of another person, which does not refer to the original.”4

However, the phenomenon of plagiarism is wider and it also includes self-plagiarism, unintentional plagiarism or plagiarism with the consent of the original author.5

To cover plagiarism in its entirety, we define it as the use (of ideas, content or structures) of another work without appropriately acknowledging the source to benefit in a setting where originality is expected.

After an intensive debate and consideration of various definitions available in academic literature, the project team of CDP “Strengthening the prevention of plagiarism in student work” has deemed the following definition5 most fitting: “The use of ideas, content, or structures without appropriately acknowledging the source to benefit in a setting where originality is expected.” This definition is developed from definitions published earlier.6,7 It includes any form of content, that is text, images, tables, mathematical formulae, etc. By ‘structures’, in the definition we mean the structures of the work (for example titles and chapter arrangement), methods of argumentation or thought structure. Structures, therefore, do not refer directly to the content of the work, but to the way the work is constructed.

Distinguish other people’s ideas from your own

Academic texts typically combine ideas originating from other sources with the author’s or authors’ own ideas and conclusions. Drawing from other works or being inspired by another work is, naturally, perfectly in order. Without using what was developed earlier, progress would not be possible. Accordingly, the problem is not using another work, but rather not acknowledging the use. The reader is then justifiably under the impression that he or she is reading original (that is so far unpublished) ideas of the author or authors of the given work.

It is always necessary to clearly distinguish the original from the adopted, and correctly refer to the source used.

In this case, the term ‘correctly’ means that the source can be unambiguously identified and found based on the stated reference. The formal requirements of correct source referencing are determined by the specific citation norm (for detail see chapter 3). With an extremely formalistic interpretation of the definition, we could consider even formal errors in bibliography to be plagiarism. However, if such mistakes do not decrease the possibility of finding the original work, a material fulfilment of the definition of plagiarism is not established.

The condition “to benefit in a setting where originality is expected”is also important. In academic texts, originality is almost always expected (see chapter 2) and the resulting benefit is in the form of credits, grades, academic award, financial gain, recognition by the academic community, etc. There are, however, situations, where originality is not expected, or different rules may apply to source referencing. These include the production of notes for personal use or learning through reproduction of other authors’ works, during which we acquire the necessary skills but a creation of an original work is not expected.

4.1 Typical forms of plagiarism

Plagiarism typically includes:

  • the use of someone else’s findings and their presentation as the author’s own findings,
  • translation or paraphrase of another work and its presentation as an original work,
  • undeclared use of own, formerly published work (self-plagiarism),
  • incorrect citations and source referencing,
  • undeclared contributions to the work presented,
  • undeclared authorship of another person (contract cheating).

Verbatim and mosaic plagiarism

Apart from the clear scenario when the author copies someone else’s entire text without stating the source, plagiarism also includes adopting individual components of another work without making a reference to the original source of the idea, or stating it in a manner that makes it impossible to assess the extent of the adopted components. If, for example, a student copies several paragraphs word-for-word without quotation marks and he or she cites the source at the end of the copied passage, the extent of the adopted text is unclear. A similar problem arises if the citation is stated just at the beginning of a chapter although the given chapter draws on this source in several places. A further form of plagiarism is so-called mosaic plagiarism, which consists of the compilation of short text passages adopted from various sources (see image 1). Unless the student includes a citation for each adopted passage, this is plagiarism, even if all used sources are stated in the bibliography.8

Mosaic plagiarism led to the resignation of many politicians. The dissertation thesis of the former German Minister of Defence contained over 80 copied passages in more than one hundred pages. The most serious offence was a two-page-long similarity between the work and two other sources, neither of which was included in a footnote or in the bibliography. The second category of transgression of referencing integrity included text passages adopted verbatim or slightly amended, which were stated in the bibliography, but the source was not cited in the text itself. The last category was formed by passages adopted verbatim, the origin of which was stated within the text in a footnote, but they were not marked as direct quotations.

Figure 1: Mosaic plagiarism

In the master’s thesis of a former Czech Minister of Justice, 16 pages (from a total of 48) were adopted from a work defended at the same university 2 years earlier. Entire pages were identical in the theoretical parts of the theses, including grammatical errors, formatting and typos.

Paraphrasing or translation without referring to the original source of the idea

The requirement to acknowledge the origin of a text remains if the student changes the presentation of the idea adopted, for example by paraphrasing it or translating it into a different language. While the new and the original source do not show any textual similarity (and, as such, the similarity is practically undetectable by the current software tools supporting the detection of plagiarism), that does not change the fact that an idea was used from other work. If the student does not reference this work, he or she commits plagiarism. A common mistake of students is that they translate a text word-for-word, or perhaps replace some words with synonyms, and they consider the result to be a paraphrase. However, only two methods are permissible in academic writing: either we directly use the original text in quotation marks, or we express the adopted idea in our own words. But to take an original text, change some words and remove the quotation marks is certainly not appropriate.


As we have already stated, students can also commit plagiarism if they reuse their own work without acknowledgement. The definition of plagiarism above covers this by accentuating gaining a benefit. So, if someone reuses his or her own work, does not refer to it correctly and gains a benefit by it, that constitutes (self-) plagiarism. In terms of student work, that means, for example, that if a student wrote a seminar paper, submitted it for a certain course and received a grade for it, he or she cannot submit the same paper (or a part of it) as new in a different course and expect to receive another grade. The student would be assessed twice for the same paper, which is unfair.

But what if the student really needs to use his or her work twice? This might happen in a situation where the student published the principal part of his or her thesis as an academic article prior to submitting the thesis. This is, of course, more than desirable. The published part cannot be omitted from the thesis, and at the same time the student wishes to reuse the text. How to avoid committing plagiarism in this case? The student may use the article in the thesis, but he or she must state that the given text has already been published, and refer to the article correctly. You as the supervisor should be able to advise students how to proceed in specific cases, and clarify how they can avoid potential problems with the publisher’s copyright.

A similar situation occurs when a student writing a master’s thesis follows on from his or her bachelor’s thesis. This is, naturally, allowed and often desirable, but two conditions must be fulfilled: First, it must be clear when reading the master’s thesis what has been adopted from the bachelor’s thesis and what is new. And second, the student’s contribution to the master’s thesis must be significant enough to render the paper defensible.

Incorrect source referencing

Students may commit some forms of plagiarism unintentionally. Omitting a citation or another mistake might cause the reader to be unable to distinguish between ideas that have been adopted and the author’s original ideas, thus meeting the definition of plagiarism. When deciding on penalties for plagiarism, the extent of the transgression as well as intention are considered. Unintentional omission will likely carry less serious consequences than intentionally misleading the reader by citing sources that do not contain the given idea, or which do not exist at all.

Undeclared co-authorship

Problems may arise when several people are involved in producing a work. Other people’s contributions to content creation is generally not a problem, but they must always be declared. By content creation, we do not mean copyediting which does not change the ideas of the work, text formatting, typographical, language or stylistic adjustment and similar. An acknowledgement to the supervisor tells us that the supervisor guided the student methodically, but he or she was not involved in producing the text. If an individual piece of work is an output from a team project, again it is necessary to distinguish which parts are the result of teamwork and which parts can be attributed to the author. Sometimes, it is impossible to avoid copying even several pages of text, for example from a common article. Typically, when a student performs measurements in a laboratory according to a previously published methodology created within a team, it is not wrong for them to copy that methodology or part of it into his or her own work. If they do not do that, the work might not make sense. If the student tried to rewrite the methodology in his or her own words mistakes and inaccuracies may be introduced. In any case, it is necessary to clearly state which parts of the text have been copied, and provide the source.

Adopting work that is publicly available or that we have consent to use (e.g., under a Creative Commons licence, which grants a universal right to use the work) does not affect the fulfilment of the definition of plagiarism. It is a common error to think that referencing Wikipedia is not required since its content is publicly owned. This fact plays no role when it comes to the definition of plagiarism. It is someone else’s work, and if a student uses it, he or she must provide an appropriate reference to it. Moreover, it is necessary to warn students, especially in the early phases of their studies, that Wikipedia is useful for an initial familiarisation with the issue and for finding academic articles, but it is rarely a suitable source for citing.

In general, it is recommended that group projects are dealt with according to the practice common in many journals. In the case of a co-authored work, it is clearly stated who contributed and in what ways, that is who brought the main idea, who conducted the literature review, who processed data, who wrote up the body of the article, etc. In this way, the reader can have a clear idea about the contribution of each individual author.

Commissioned papers

It is, naturally, an exclusive right of the original author to grant consent for the use of his or her work without the obligation that he or she be stated as the author. That, however, does not change the fact that if we present such work as our own, we commit plagiarism. An example is socalled contract cheating (or academic ghostwriting), where a student commissions a work to be written by someone else, typically for remuneration, and the original author consents that his or her name will not be stated in the work. The student who puts his or her name to that work commits plagiarism. As such, contract cheating is a form of plagiarism which does not breach the Copyright Act, nevertheless it breaches good morals and academic integrity, and, according to the Higher Education Act, this conduct constitutes a potential reason for expulsion from the study programme or removal of an existing academic award. A great risk associated with contract cheating is also the fact that the plagiarist can easily be subsequently blackmailed by the actual author of the text, the intermediary company or a different entity familiar with the fraud.

4.2 What is not considered to be plagiarism

Using common knowledge

The definition of plagiarism refers to ideas adopted from another work. For many ideas, however, it is not possible to identify what work they come from. This concerns so-called common knowledge. Facts that are universally known may be stated without a source reference. Nevertheless, it should be recommended to students to use common knowledgesparingly. That is because it does not increase the information value of the work. Its use is reasonable in the introduction, discussion or conclusion sections of the work as a prelude to other (own or adopted) ideas. The definition of common knowledge may change according to the field and the reader’s expected familiarity with the topic. Accordingly, that which is known by the vast majority of the presumed readers can be considered to be common knowledge. If a student is uncertain as to whether a given information is common knowledge or not, and he or she does not have the chance to consult the specific instance with a teacher, he or she should include a reference. It is also necessary to be prepared for the situation where a student who committed plagiarism defends himself or herself by arguing that the copied information is common knowledge.

Proofreading, copyediting, translation

If the external contribution to the work does not affect its ideas, we do not consider it to be plagiarism. This includes, for example, as already mentioned, copyediting or typographical adjustments. In the case of translations, the author of the work remains the same. It is appropriate to acknowledge the contribution of the translator, but in no case may the translator be stated as the author of the text.


Plagiarism may appear in many forms and arise in many ways. The common sign of plagiarism is always the adoption of someone else’s work or part of it, and not declaring the original source (whether the text or the idea is adopted verbatim, paraphrased or translated from a text in a foreign language). Students should not be afraid to use sources in their texts; on the contrary, their use is desirable. However, students must be guided to always clearly mark any adopted passages and their source so that the reader can distinguish between their own contribution and the contribution of work by different authors.

  1. ČSN ISO 5127 (010162) Informace a dokumentace – Slovník. Praha: Český normalizační institut, 2003. Česká technická norma.
  2. Celbová, I. Plagiát [heslo]. In: KTD: Česká terminologická databáze knihovnictví a informační vědy (TDKIV) [online]. Praha: Národní knihovna ČR, 2003– [cit. 2020-10-29]. Dostupné z: https://aleph.nkp.cz/F/?func=direct&doc_number=000002675&local_base=KTD.
  3. Foltýnek, T., Meuschke, N., Gipp, B. Academic Plagiarism Detection: A Systematic Literature Review. ACM Comput. Surv., 2019, 52 (6), 112:1–112:42. DOI: 10.1145/3345317.
  4. Meuschke, N., Gipp, B. State-of-the-art in detecting academic plagiarism. International Journal for Educational Integrity, 2013, 9 (1), 50–57.
  5. Fishman, T. ‘We Know It When We See It’ Is Not Good Enough: Toward a Standard Definition of Plagiarism That Transcends Theft, Fraud, and Copyright. In Proceedings of the 4th Asia Pacific Conference on Educational Integrity (4APCEI), 2009.
  6. For a more detailed description of individual forms of plagiarism, we recommend this publication: Walker, J. Student Plagiarism in Universities: What are we Doing About it? Higher Education Research & Development, 1998, 17 (1), 89–106. DOI: 10.1080/0729436980170105.