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“How Many Recipes for Chocolate Cake Do We Need?” or When Does Similarity Become Self-plagiarism?

Hinds, Pamela S. PhD, RN, FAAN

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doi: 10.1097/NCC.0000000000000679
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In a recent, thoughtful exchange with a colleague for whom I have great regard and trust, we spoke of our divergent views regarding “similarity coefficients” produced by manuscript software review programs, she from the perspective of a well-published author and well-funded researcher and me from the perspective of an editor-in-chief. She shared her frustration over receiving a notice from a journal editor that her submitted manuscript had too high of a similarity coefficient with her previously published works to be accepted into the journal's peer-review system. In particular, the high coefficient was related to the Methods section, which contained the same wording being used by this talented researcher in all previous publications from the same funded study. After all, she added, the Methods section is a recipe and as such should be the very same across publications. But, the editor in me responded, “How many chocolate cake recipes do we need in the same cook book when there are a very limited number of pages available for all recipes?”

With a respectful nod to chocolate connoisseurs, I acknowledge that variations of a chocolate cake recipe may be called for if the overall purpose of the cake differs (eg, made for a person with certain food restrictions). But once the recipe is publicly available to all who seek it, why would we continue to add that same recipe to other sites that are equally available to all? When does the recipe become duplicative and unnecessary? When does the author risk being thought of as committing self-plagiarism?

Plagiarism of self occurs when authors reuse their own written work in part or in full as if it was new in its subsequent uses.1,2 There is some disagreement about whether one can plagiarize oneself and additional discourse about who comprises the “self” when the published work is authored by a team,3 but there is no disagreement about how self-plagiarism infringes upon a publisher's copyright. In copyright forms, each author signs the agreement pledging that the work is original and has not been previously published, in part or in whole.4

In the publishing world, we have 4 important tools to detect plagiarism—of self or of others. A most important tool is peer reviewers who bring content and methodological expertise to bear on each manuscript that they review. These are individuals knowledgeable about the field represented in the submitted manuscript. But with the proliferation of knowledge across fields, peer reviewers cannot be expected to be intimately aware of all of the field's publications, so this expert resource cannot be singularly responsible for detecting use of same or highly similar wording to previous publications.

Our second tool is a software program. Upon submission to Cancer Nursing: An International Journal for Cancer Care, a manuscript is immediately and automatically reviewed by this software and a similarity coefficient is produced. The sections in a manuscript that are contributing most to the coefficient are highlighted. High coefficients result in the manuscript not being accepted into the journal's peer-review system. The highlights could include a verbatim Methods section published previously whether in this journal or another journal. Of relevance, if the Methods section is already in the public domain, that original citation can be noted and the entire section not repeated in subsequent publications. This approach of citing one's previous work is recommended in the current manual of the American Psychological Association.2

The third tool is other authors who recognize their research or that of others being incorporated into the papers but without proper attribution of the original source. This important tool can be useful during the peer-review process or as soon as a manuscript is placed into the ahead-of-print system. But always, the most important tool is the fourth tool: commitment to writing integrity of the study team and a regard for the space available for all publications. If content has been previously published and is not essential to the readers' understanding of the content in the new manuscript, abbreviating that content and citing the original source where the full details are included would be respectful of the research, the study team, and the publication space available in target journal.

As I close this editorial, may I add that my family and I welcome receiving your recipe for chocolate cake, and as an editor, I welcome your manuscripts that contain the essential contents necessary for our readerships' understanding of your good works.

My very best,

Pamela S. Hinds, PhD, RN, FAAN
Editor-in-Chief Department of Nursing Research and Quality Outcomes Children's National Medical Center, Washington, DC


1. American Association for the Advancement of Science. A fresh look at self-plagiarism. Accessed October 11, 2018.
2. American Psychological Association. The Publication Manual of the American Psychological Association. 6th ed. Washington, DC; 2010.
3. The Office of Research Integrity. Self Plagiarism. Accessed October 11, 2018.
4. Blackman J. Self-Plagiarism. Accessed October 11, 2018.
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