What is self-plagiarism and how can you avoid it?

Plagiarism generally involves using other people’s words or ideas without proper citation, but you can also plagiarize yourself.

Self-plagiarism means reusing work that you have already published or submitted for a class. It can involve re-submitting an entire paper, copying or paraphrasing passages from your previous work, or recycling old data.

Self-plagiarism misleads your readers by presenting old work as completely new and original. If you want to include any text, ideas, or data that already appeared in a previous paper, you should always inform the reader of this by citing your own work.

Examples of self-plagiarism

Common forms of self-plagiarism by students include:

  • Handing in a paper you’ve already submitted in another class.
  • Pasting sections or paragraphs from previously submitted work into a new paper.
  • Reusing data or ideas from your bachelor’s thesis and building on them in your master’s thesis without citing the original work.

Common forms of self-plagiarism by academics include:

  • Using a dataset from a previous study (published or not) without making the reader aware of this.
  • Submitting a manuscript for publication containing data, conclusions or passages that have already been published (without citing your previous publication).
  • Publishing multiple similar papers about the same study in different journals.

How to avoid self-plagiarism

If you’re unsure whether something counts as self-plagiarism, first check the plagiarism policy of your university or the journal you’re submitting to. If there is no explicit policy on self-plagiarism, follow these guidelines.

For students

  • Do not reuse your old assignments. You might be assigned a topic that you’ve already written a paper on. Never submit the same paper again, even in a completely different course. If you want to cover some of the same ideas in your new paper, then…
  • Talk to your instructor. Your professor can tell you whether it’s acceptable to reuse or rework parts of old assignments. This is sometimes the case, for example, if you want to build on a previous paper in your thesis or dissertation.

For academics

  • Do not reuse previously published work. Publishing a paper that reuses part of an already-published text could constitute a copyright infringement and misleads readers. Make sure every part of your paper is original and written from scratch.
  • If you use old data or ideas, always inform the reader. You might want to build on research you’ve published elsewhere. As long as you use the material in a new and original way, and you properly cite the publication where it originally appeared, this is generally acceptable.

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Consequences of self-plagiarism

For students

Self-plagiarism is not as serious as some other types of plagiarism, but your university will probably have a specific policy on self-plagiarism.

At most universities, violation of the plagiarism policy results in an automatic zero and possible suspension or expulsion.

University departments will often allow some reuse of work under certain conditions, but make sure you fully understand the policy to avoid these consequences. If your university allows you to reuse your old work, be sure to check with your professors and get permission before doing so.

For academics

The two biggest consequences for an academic or researcher who self-plagiarizes are:

  • Delayed or rejected publication
  • Copyright infringement

If your article is too similar to one of your previously published works, the journal is likely to reject it. Most journals will list their plagiarism guidelines along with their submission requirements, so make sure to check the specific policy.

Even if the journal allows resubmission of previously published work, you also have to check whether the original publisher owns the copyright of your paper. If you publish large chunks of the same material elsewhere (even with citation), you might be infringing copyright, which could have legal consequences.

Conclusion: can you plagiarize yourself?

Yes. Self-plagiarism seems to exist in a confusing grey area, but like all plagiarism, it’s about academic honesty: readers should be able to trust that your submitted work is genuinely new and original. As long as you double-check the relevant plagiarism policies and cite properly, you can easily avoid committing self-plagiarism.

If you’re still unsure about plagiarism, read more about the types of plagiarism, use our plagiarism checker or take a look at our in-depth comparison of the best plagiarism checkers for students.

Frequently asked questions

Is it plagiarism if you cite the source?

If you correctly cite the source you do not commit plagiarism. However, the word 'correct' is vital in this sentence. In order to avoid plagiarism you must adhere to the guidelines of your citation style (e.g. APA citation style or MLA citation style).

Plagiarism checker software can be used to check your text for plagiarism. This software compares your text with billions of webpages, books and articles.

Scribbr Plagiarism Checker

What is the difference between plagiarism and paraphrasing?

Plagiarism is the act of using someone else’s work or ideas without crediting the original author and thereby pretending it’s your own.

Paraphrasing means rephrasing the original text in your own words.

So, where does the confusion come from?

When using someone else’s work, you can either quote or paraphrase it to prevent plagiarism. Paraphrase a text if you want to clarify or shorten the original text. Quote the text if you want to keep the exact wording and meaning of the original source.

What happens if you plagiarize?

The consequences of plagiarism vary depending on the severity of the infraction. Some types of plagiarism, such as direct plagiarism, are more serious than others, such as self-plagiarism.

If you’re a student, then you might fail the course, be suspended or expelled, or be obligated to attend a workshop on plagiarism. It depends on whether it’s your first offense or whether you’ve done it before.

As an academic or professional, the consequences are more serious. Aside from the fact that plagiarizing seriously damages your reputation, you might also lose your research funding and/ or your job.

Plagiarizing is a serious offense, and knowing how to avoid plagiarism is therefore important. Read more about the consequences of plagiarism and use a plagiarism checker to detect plagiarism yourself.

Are plagiarism checkers accurate?

The accuracy depends on the plagiarism checker you use. Scribbr is the most accurate plagiarism checker. Many free plagiarism checkers fail to detect all plagiarism or falsely flag text as plagiarism.

Take a look at this comparison of free and paid plagiarism checkers for students to find the most accurate plagiarism checker.

The accuracy is determined by two factors: the algorithm (which recognizes the plagiarism) and the size of the database (with which your document is compared).

Size of the database

Many free plagiarism checkers only check your paper against websites – not against books, journals or papers previously submitted by other students. Therefore, these plagiarism checkers are not very accurate, as they miss a lot of plagiarism.

Algorithm

Most plagiarism checkers are only able to detect “direct plagiarism”, or instances where the sentences are exactly the same as in the original source. However, a good plagiarism checker is also able to detect “patchwork plagiarism” (sentences where some words are changed or synonyms are used).

Should I check my paper for plagiarism before submitting it to my instructor?

If you’ve correctly cited all the sources you used, then you do not need to use a plagiarism checker before submitting your paper to your instructor. However, if you want to be sure that you didn’t forget to cite anything, then you can use a plagiarism checker yourself.

There are both free plagiarism checkers and paid plagiarism checkers, such as the Scribbr Plagiarism Checker.

To help you, we compared popular plagiarism checkers to find out which one is best.

Best plagiarism checker comparison

Still have some questions? Here are some sources we found helpful:
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Raimo Streefkerk

Raimo is an expert in explaining plagiarism and citing sources. He has been writing helpful articles since 2017 and is continuously improving Scribbr's Citation Generators.

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