I'm currently writing my second paper.

Although the focus is completely different of my first paper, some aspects of the context are similar.

I am perfectly aware that self-plagiarism needs to be carefully avoided but what is the limit?

Indeed, a couple of sentences of my abstract or introduction are very hard to reformulate without making the sentence significantly harder to understand or really longer.

In this context, is it tolerable to reuse a single sentence in the abstract and/or in the introduction?

Edit: I forgot to mention that the submission is anonymous. This is why I'm so picky about self-plagiarism.

  • 2
    Of course it is tolerable, don't be silly. If it was a whole paragraph, you would have to think about presenting it as a quote, though. Jun 10, 2020 at 18:25

3 Answers 3


You have a misconception. Plagiarism isn't about the actual words. It is about ideas. Copyright can cover the expression of the ideas (the words). In other words, you can plagiarize even with a complete rephrasing of the original. But it is easy to avoid.

To avoid self plagiarism all you need to do is cite the original work. I'm assuming that the words you use are expressing the same idea though in a different context. And if you cite and you hold copyright then there are no issues at all. If you don't hold copyright then you either need to get permission from the holder or depend on one of the exceptions to copyright law (which varies from place to place). You may well be able to claim fair use. You might also be able to claim that your reuse of the sentence doesn't reduce the value of the original. Those are valid in some places. And some ideas can only be effectively expressed in one way.

The reason to avoid self plagiarism is a bit different from that to avoid ordinary plagiarism. A reader of a new work may need to find the complete context of the ideas. This includes other words and references, etc. If you don't cite, then that chain is broken for a researcher. This also applies to ordinary plagiarism, but the need to not claim the work of others as your own is typically thought to be the more important part there.

  • Very insightful answer. I should have mentionned that this submission is anonymous though. Does it changes anything?
    – Maxime B.
    Jun 11, 2020 at 21:42
  • 4
    Copyright really doesn't enter into plagiarism. You can plagiarize without violating copyright, and you can violate copyright without plagiarizing, whether the work is your own or someone else's. Jun 11, 2020 at 21:42
  • @ScottSeidman, yes, but newcomers to the game often get the issues confused so I try to show the essential elements of each in such answers.
    – Buffy
    Jun 11, 2020 at 21:52
  • And no, an anonymous submission changes nothing. It would only be different if the early paper weren't published (and won't be).
    – Buffy
    Jun 11, 2020 at 21:54
  • Copyright is a bit misleading here. There is a good chance, that you basically sold the copyright or an exclusive license to the publisher, but you are probably still fine copying a few sentences (with the mentioned limitations), because you are the author (which is more about plagiarism than copyright).
    – allo
    Jun 12, 2020 at 12:26

I think you should differentiate between reusing single sentences that are just a normal way of conveying certain information, and reusing ideas/concepts.

For example, most of my papers deal with the same disease. I always describe this disease with the exact same sentence in the Introduction section (i.e. it's characterized by these and these symptoms, median survival is 5 years). I see no need to formulate that kind of information differently in each paper. I do not cite my own papers for this and do not make it a quote. This kind of thing is totally ok and not considered (self) plagiarism.

On the other hand, I also have a paper describing a certain method and then follow-up papers that use that method somewhere. In these sections I also sometimes repeat exact sentences, but I do cite the previous paper. Here it is an original idea that I'm reusing and I shouldn't give the impression I came up with it anew in each paper.

The submission being anonymous does not change anything; if the reuse is significant enough to warrant a citation, you need to cite, regardless whether the original work was written by you or someone else.

In short, repeating exact sentences is in many cases acceptable; whether a citation is needed depends on what kind of information in conveyed in that sentence. You are in the best position to judge in which category your reuse falls.

  • I think some of your usage falls under the heading of "only one effective way to state an idea".
    – Buffy
    Jun 12, 2020 at 22:10
  • Yes, true. But since you stated that in a paragraph that starts with "To avoid self plagiarism all you need to do is cite the original work." , I got the impression this was more about formulating an original idea the same way each time. With my answer I just wanted to clarify that not every reused sentence warrants a citation.
    – Maximus
    Jun 13, 2020 at 7:00

I would argue there are no limits here, simply because the idea is nonsensical. I think citing the original work is helpful, but calling your own ideas, repeated, "plagiarism", is bizarre.

Just cite the work for others to know it has appeared elsewhere.

Also, articles should not really overlap much if at all possible. Easy to cite and save time.

  • Sorry, but this is lazy practice. I won't even call it "scholarship".
    – Buffy
    Jun 12, 2020 at 15:50
  • It is not plagiarism to write you’re own points twice. But still, cite it. It just confuses phd students.
    – apg
    Jun 12, 2020 at 15:57
  • Who gets to decide these things? And what are the consequences for failure? That’s why you should rename it “overlap” or “repetition”.
    – apg
    Jun 12, 2020 at 15:58
  • It is fine if you are writing an op ed or letter to the editor of your local newspaper. But not for scholarship. The consequences are academic community condemnation.
    – Buffy
    Jun 12, 2020 at 16:12
  • Only the academic community know the meaning of “self-plagiarism”, and even that is apparently debatable. What would the outsiders think? Can anyone give an example of this going wrong? Any act of self-plagiarism at all? Plagiarism on the other hand is widely understood and disrespected.
    – apg
    Jun 12, 2020 at 16:41

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .