Max is finishing his master's degree. He is asked to write a thesis to demonstrate his academic training. He chose to address a topic he had already studied before and wishes to continue this work. Only, he wonders if this is going to be considered self-plagiarism. As we know, plagiarism is attributing others' work to yourself. And, when you reuse an old assignment, you might think you're not harming anyone. Why waste time writing new content if you've already covered the subject in a previous assignment?

When working on an individual written production, (report, dissertation, thesis, article or essay..) whenever existing texts are quoted, it is imperative to apply citation rules even if the author is the same as the original document. Since it is a different work, it is important to lay out what constitutes the «old» production and what belongs to the «new» production.

 

Self-plagiarism according to the French National Centre for Scientific Research (CRNS)

« Self-plagiarism occurs when an author partially or entirely « recycles » previously published content without citing the sources. This practice can constitute a breach of ethic rules if the document or the excerpts recycled were already published since they do not comply with the duty of only submitting original works. » 1

Why is it serious?

Self-plagiarism deprives the reader of his rights

Self-plagiarism is not to be taken lightly! According to Michelle BERGADAA, a plagiarism specialist, « self-plagiarism is one of the most concerning cases of lack of scientific integrity ». Although « self-plagiarism might not be a theft of others' ideas », it still robs the reader of his « fundamental right […] to access original sources and knowledge ». 2

 

Self-plagiarism skews evaluations and games reward systems.

What is at stakes here is not only a clear identification of the author (who in this case is the same), but also the understanding that minor or substantial portions of the text come from a previous work , and are consequently , not part of a new production.

How then can it be possible to assess  the new effort made as well as the input of new concepts and ideas ?                                                                                                                                                                                                           

Should we consider normal the fact that someone might be rewarded multiple times, sometimes even paid several times for a work that has simply been duplicated? 3

 

Plagiarism and self-plagiarism: equal sanctions

 Therefore, saying that « duplicating your own work is not plagiarism » cannot be considered a powerful defense argument against accusations, contrary to what Etienne Klein, a science philosopher, has claimed when he was accused of self-plagiarism. 4
In all cases, it is important to be transparent with the reader. When citing one’s own workquotation marks and references to the original work are required. Otherwise it will be considered as self-plagiarism; knowing that self-plagiarism just like plagiarism, can be sanctioned.

Self-plagiarism: how do I avoid it?

In an individual work (report, thesis, dissertation, article, essay, etc.), when quoting pre-existing texts, you must follow citation rules. The same applies if you yourself are the author of the original document. To cite yourself, follow the same steps as for other citations: put the quoted text in quotation marks, indicate the author, the title of the document and its date.

Indeed, since this is a separate work, it is important to distinguish what is part of the “new” work from what is from “previous” work.

Some students may be tempted to rephrase words used in another document so as not to have to cite themselves. Paraphrasing is a form of plagiarism, even when it involves your own research. This shortcut is therefore not a valid option.

Furthermore, it is important to supplement your personal evolution of thought. The goal is to show the reader a certain growth from the learning process.

Note, the names of all authors, documents used while writing, borrowed text, and citations must appear in a detailed bibliography in order for copyright to be respected.
Max, you now understand that reusing old work is not creative; it's self-plagiarism. The reader expects to see original research work. Citation rules apply for all borrowed content, even your own. Self-plagiarism is punishable like regular plagiarism. Thus, you are allowed to use your own words taken from another document, provided you mention the source.

Sources :
1 – Comité d’éthique du CNRS, Promouvoir une recherche intègre et responsable, July 2014.
Available 
here.
2 – Bergadaà M., Autoplagiat, Plagiat et fraude scientifique, June 20th, 2013.

Available here.
3 – Wager E., Why is Redundant Publication a Problem?, 2015.

Available here.
4- Maouche S., L’ « affaire » Étienne Klein : « Se recopier » est un auto-plagiat, Médiapart, December 8th, 2016. Available 
here .