I just wanted to see what people think about a possible plagiarism issue. I found a new article which, as far as I can tell, uses data first shown in an older publication from the same group but with a different first author. This may be irrelevant but I thought I'd mention it anyways; this new article's only novelty is to analyze the old data with a model developed in another group.

To the point: this new article has many (more than 8) sentences taken from the older article from the same research group. These sentences describe the experimental setup. It's clearly the same setup as the older article.

Is this plagiarism? I've been taught that it is but I've talked to another academic who says it's not since there are only a limited number of ways that methods can be explained.

  • Do they cite the old paper where these methods were first discussed? Oct 25, 2017 at 14:44
  • 1
    Yes, they cite that old paper.
    – ZacHammer
    Oct 25, 2017 at 16:00
  • Suggesting quotation marks is a job for some people.
    – user56983
    Mar 3, 2018 at 15:24

3 Answers 3


Experimental and methodology sections are increasingly being recognized as "exceptions" from plagiarism, for reasons of practical necessity. For instance, I use the same basic technique to study different problems in engineering and material science. One of the sentences in my methodology section is:

We use the SHAKE algorithm to constrain the bonds in water molecules [citation].

There are only so many ways to write this statement, and at the same time, I can't ignore this information, because it would imply a change in method. Is it plagiarism for me to reuse the same wording as in an earlier paper? If it is, I'm in big trouble. Similarly, if I were an experimental group, how many ways are there to say:

We used chemical X from vendor Y as received.

For this reason—because often methodologies are very similar to previous methodologies within a research group–many journals now do not consider such so-called "self-plagiarism" of the methodology section to be a problem.

  • If a methodology is common to many papers, then reusing a description of it (with citations to previous use) is not plagiarism: the ideas are manifestly not original, and the language is viewed by those in the field as being routine rather than distinctive. Still, I think one should keep verbatim copying below a certain threshold.... Oct 26, 2017 at 3:10
  • ....I don't read papers with methodology sections, so let me explain it in terms of my own field. If you are quoting a theorem, no one would ever say "Hey, your statement of it is exactly the same as X's; why didn't you change it?" That would sound nuts. On the other hand, if I state a sequence of theorems in a manner identical to a previous paper, then after a certain point one wonders why the reader is not just referred to the previous paper. Oct 26, 2017 at 3:15
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    I was thinking along the same lines as @aiesmail . Especially in the biomedical sciences one lab may produce a series of methodologically near identical papers where I'd consider it highly desirable to not try to gratuitously vary the description. It's hard enough to follow the exact steps, and any variation might induce the question whether the description means a variation to the process. In the literature I see a lot of hand-wringing about the "problem" of how to avoid self-plagiarism, while offering consistent, standardized methods, and I think that's a pendulum swinging too far.
    – chryss
    Oct 26, 2017 at 3:55
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    @PeteL.Clark "If a methodology is common to many papers, then reusing a description of it (with citations to previous use)" I disagree that there has to be a citation. Our experimental parts always start with a discription of the commercially available instruments used. There's no point in rewriting this part and it would just be stupid to cite a previous paper since it wouldn't provide any information other than "we used that instrument before" which is irrelevant for the presented work.
    – user64845
    Oct 26, 2017 at 4:02
  • @DSVA: I didn't say that there has to be a citation; my comment was of the form "under these conditions there is no plagiarism". That does not imply "under other conditions, there is". I am working in a very different academic field from you (no experiments!) so in many cases I simply don't have an informed opinion. I'm curious though: how long are the repetitious parts of your papers? Under a page? Over a page? Oct 26, 2017 at 5:15

Plagiarism is presented to students as a binary concept: either you're doing it or you're not, and you'd better not, because if you do it there are clearly defined repercussions meted out by a clearly defined group of people, the academic honesty personnel at the university.

In post-student academia, the truth is that plagiarism functions more as a continuum. Instead of one set of rules that all the world's academic members agree upon, there are less precise (though no less deeply held) cultural norms that most of the world's academic members mostly agree upon. There is also no good analogue in the "real" academic world of "academic honesty personnel": instead, academia is largely self-policing.

So in your case, instead of asking "Is it plagiarism?" you should be asking "Is this an academic best practice? If not, how bad is it? Is it actionably bad?"

In the case at hand:

[T]his new article has many (more than 8) sentences taken from the older article from the same research group. These sentences describe the experimental setup. It's clearly the same setup as the older article.

My view on this is: it's far from being bad enough to merit any outside corrective action. Because the word "plagiarism" sounds very serious and we in academia have a stake in keeping it that way, I would not use that word in this instance. (And if you do, your colleagues / superiors / affiliates may think you're overreacting.) Three key points:

  • Plagiarism is defined as using the ideas and/or distinctive language of someone else. I gather from your description that the two papers were written by the same group. (You say "with a different first author". I don't see the relevance of that -- all the authors of the paper are all the authors of the paper when it comes to issues of academic integrity and citation.) Recycling your own work is a different academic crime, often called "self-plagiarism," but I discourage people from using the term "plagiarism" to describe it: it gives the wrong idea.

  • You say that they cite their older paper. That's a key point in their favor -- it means they are not trying to fraudulently pass off old work as being new. One can even argue that the paper went through the refereeing process and the referees and the editors apparently had no issue with the repetition. (That doesn't necessarily make it okay, but it provides some useful perspective.)

  • The essential currency of academic work is intellectual novelty, but that does not mean that everything that appears in an academic work is or should be intellectually novel. There is a certain amount of routine, procedural stuff that needs to be there, but that most expert readers will quickly pass their eyes over.

I hope you notice that at no point did I claim that the authors have followed best practices here. I do think it's lazy to lift multiple sentences and whole paragraphs from a previous work. In my opinion, even if something is completely routine and what you write is going to read the same way as what many other people have read before: okay, then you can type up a new, uncopied version quickly and easily. Also, as a reader, when you catch someone copying anything, your opinion of them and the novelty of their work goes down a bit.

I will end with this: I remember once, some years ago, reading a paper of a certain student of one Professor A and having the feeling that the paper was morally similar to a paper of Professor A's that I had glanced at before. When I compared the two papers side by side, I found that not only was the intellectual content closely analogous, but the student had evidently written the introduction to his paper by starting with the introduction to Professor A's paper and making close to the minimum possible amount of change necessary for the same text to introduce his own paper. I did not seriously consider pursuing a plagiarism charge on the student...but it left me with a negative impression of his creativity, independence and work ethic. From what you say about the two papers, the main issue is not that some routine procedural passages were copied, but really that the second paper is rather derivative on the first -- not fraudulently so, but in a way that makes the second paper not that interesting to you. That you think this about the authors' work is, I think, the most appropriate negative consequence of their actions.

  • I would argue that in some cases citing the older paper can actually be less 'ethical'. If you consider the situation where the authors use essentially the same experimental technique in two different papers and describe it with the same wording, but that the technique itself is not novel and they were not the first to do it, then citing their previous paper could seem like an unjustified/frivilous self citation. Of course it is always possible to reword sentences to satisfy some arbitrary rules about 'self citation' (or copyright), but in many cases this serves no sensible purpose.
    – Bobgom
    Oct 26, 2017 at 1:29
  • @Bobgom: I agree that a more primary citation is to be preferred. In terms of reusing common, routine text: some positive amount of this is certainly okay. On the other hand if, say, three pages of text were copied verbatim from the previous paper, that would not be okay -- no academic paper should contain this amount of derivative content -- and doing this without a self-citation would make it much worse, since then the derivative-ness is being hidden from the referees and readers. Oct 26, 2017 at 3:01

Does the new article cite the older article, or otherwise address the older article? If not, I would say it's almost certainly plagiarism. If the author's of the new paper did, in fact, quote the older paper, and not give it an in text citation, they could be considered plagiarists, but are more likely just sloppy writers.

I think that the 'other academic', you referenced, is probably incorrect. Their statement is true to some degree, but I cannot think of a single instance, except for a definition or law, where there is only a single way to phrase a statement like you described.

If you don't think my answer was clear enough, I'd recommend running the paper through a plagiarism checker. Many schools do this, and they are often the final word in discussions like this.

  • There may not be a single unique way to say something, but if I use the same methodology in forty different papers, do I need to find forty different ways to say it?
    – aeismail
    Oct 26, 2017 at 1:21
  • @aeismail Plagarisim is copying someone else's work without due acknowledgement. Even if you copied yourself, you would have a defense against plagiarism because it would be yourself. If you really want to make it clear it is work done based on prior work, you can always reference yourself.
    – Edwin Buck
    Dec 18, 2017 at 22:01

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