Ethical Publishing Practice

Overview

PLOS is a member of the Committee on Publication Ethics (COPE). PLOS journals abide by COPE’s Code of Conduct and aim to adhere to its Best Practice Guidelines.

Authors, editors, and reviewers are expected to be aware of, and comply with, best practice in publication ethics.

• Authors are expected to be aware of, and comply with, best practice in publication ethics including but not limited to those pertaining to authorship (for example avoidance of ghost or guest authorship), dual submission, attribution, plagiarism, image integrity and figure preparation, and competing interests. Authors must also comply with PLOS policies on research ethics (human subjects research, animal research, global research). Details are provided below or in linked documents.

• Reviewers and editors are required to treat manuscripts fairly and in confidence, and to declare any competing interests. Editors should also abide by the code of conduct for editorial board members.

We encourage readers to discuss the scientific contents of PLOS articles directly with corresponding authors, either by emailing the corresponding author or posting a comment on the article’s PLOS webpage (see here for information about posting comments). Authors can request formal corrections to their PLOS publications by emailing the journal office.

If you have concerns about potential errors, research or publication ethics, misconduct, or other issues pertaining to the integrity, validity, or reliability of a PLOS article or submission, please contact PLOS directly. To do so, email the PLOS Publication Ethics team and cc the journal office. Do not rely solely on posts to blogs, social media, or other third-party websites to make us aware of concerns. When notifying PLOS of concerns, provide the full citation and DOI of the article in question, details as to your specific concerns, and a declaration of any potential competing interests you have with regard to the authors, funders, and/or sponsors of the article(s) in question.

PLOS will investigate concerns raised about PLOS submissions or publications regardless of the time since publication or study completion, and regardless of whether issues are raised internally, by authors, or by anonymous, pseudonymous, or named third parties. We will take steps to correct or clarify the scientific record if necessary, which may include issuing a editorial note, correction, expression of concern, or retraction. If we anticipate a delayed or prolonged follow-up period PLOS may post an interim notice on the article(s) in question to make readers aware of the issues raised.

While PLOS values transparency in scientific communications, we also protect the confidentiality of those who raise publication ethics or research integrity concerns, where possible, so as to minimize personal and professional risks to those individuals. We consider information and materials received in ethics case follow-up discussions as confidential, but we reserve the right to share relevant information with others involved in the case (e.g. editors, reviewers, other journals, affected data repositories), discuss the case at a COPE forum, and/or contact authors’ institutions, funders or regulatory bodies, in accordance with COPE guidelines. We cooperate with institutions looking into issues that pertain to PLOS content, and in doing so we share information as needed to support the institution’s proceedings.

All who raise concerns to PLOS, inquire about issues raised to PLOS, or are otherwise involved in publication ethics cases must comply with the Standards for Professional Conduct policy.

PLOS Publication Ethics Team

PLOS has a central Publication Ethics team comprised of Editors who have scientific and editorial expertise as well as specialized expertise in the policies, workflows, and industry-wide guidance pertaining to ethics and integrity issues (e.g. from COPE). The Publication Ethics team supports and collaborates with all PLOS journals, and follows up on concerns raised to PLOS that have implications for the integrity, validity, or reliability of submitted or published articles. The Publication Ethics team also contributes to the development of PLOS policies pertaining to research and reporting ethics.

To contact the Publication Ethics team, email pub-ethics@plos.org.

Ethical Peer Review

We are committed to ensuring the integrity of the peer review process, in accordance with COPE guidelines.

Compliance with PLOS policies

Reviewers and editors must comply with all PLOS policies, including but not limited to this Ethical Peer Review policy, the Code of Conduct for Editorial Board Members, and PLOS policies on Standards for Professional Behavior, Confidentiality, and Competing Interests.

All editors and reviewers should consider whether they may have potential competing interests before accepting an invitation to evaluate a submission for PLOS. Please contact the journal office (complexsystems@plos.org) if you have questions about whether you should accept/decline an invitation to contribute to peer review for PLOS.

• Editors are expected to decline invitations to handle submissions for which they may have a potential competing interest.
• Reviewers should declare any potential competing interests on the review form, and should decline invitations if competing interests may impact one’s ability to provide an objective and unbiased evaluation.
• If a reviewer has declared a competing interest, the handling editor should consider potential impacts of the conflict when evaluating the reviewer’s comments, and secure at least one review from an individual who does not have a potential conflict.

The peer review process

Reviewers and editors are responsible for the contents of their reviews and decision letter comments, respectively. Reviewer and editor comments should reflect their own personal assessment of the content, including whether the submission meets the journal’s requirements and complies with PLOS policies.

Reviewers must declare on the review form if they obtained any third-party support for their review; the name(s) of anyone providing such support must be provided. Unpublished submissions should not be shared (including within one’s research group) with anyone who is not declared as a contributor to peer review. All relevant sources should be cited in the review or decision letter comments. Everyone who contributes to peer review is expected to abide by PLOS policies and the journal’s best practices for reviewers.

Authors, editors, and reviewers must not attempt to influence others’ contributions to peer review, and editors and reviewers must not attempt to use or manipulate the peer review process for personal gain.

Editorial board members must not alter review content. Concerns about comments in reviews or decision letters should be referred to the journal office and PLOS staff will intervene or follow-up as needed. However, editors are welcome to use the body of the decision letter to inform authors if a reviewer’s request does not need to be addressed in revisions, for example if the editor considers the request as optional or out of line with PLOS policies, or if the editor disagrees with the reviewer’s comment.

Artificial intelligence (AI) tools in peer review

Peer review feedback and decision letters should reflect reviewers’ and editors’ personal assessments of submitted content. AI tools cannot serve as reviewers or as decision-issuing editors.

Any use of AI tools in peer review (e.g. for data assessment, translation, or language editing) must be clearly disclosed to authors in the review form (reviewers) or decision letter (editors).

As is noted in our Confidentiality policy, unpublished submission content must be held as strictly confidential. Editorial board members and reviewers should not upload submissions to web platforms, databases, generative AI tools, or other services.

Please email the journal office and cc pub-ethics@plos.org if you have questions or concerns about AI tool usage in peer review.

Protection of reviewer identity and the use of pseudonyms or false names

PLOS gives reviewers the option of signing their names to reviews. Under no circumstances should editorial board members disclose a reviewer’s identity to the authors or to other third parties (except in the context of discussions between the editor and PLOS journal staff or Editors-in-Chief). Editorial board members should escalate to PLOS any requests about reviewer identity.

Likewise, PLOS staff protect reviewer confidentiality where possible. However, PLOS staff may disclose a reviewer’s identity under select circumstances, which include but are not limited to:

• disclosing a reviewer’s name and involvement in a submission’s prior review to an editor handling a resubmission or appeal,
• providing information about a publication ethics case to an institutional official, and
• situations where PLOS is required by law to disclose such information (e.g. a subpoena to produce documents).

Reviewers must use their legal or professional names in their PLOS Editorial Manager accounts, and should provide their current institutional affiliation and institution-hosted email address in their Editorial Manager profiles. Reviewers must not impersonate others or use pseudonyms or false names in their PLOS accounts. Reviewers and editors are responsible for ensuring that a secure, direct email address is used for all peer review correspondence; shared accounts should not be used.

How to report concerns about unethical practices in peer review

Please email pub-ethics@plos.org and cc the journal office if you have questions or concerns about compliance with this policy, or if you are aware of issues that may impact the integrity of a PLOS submission’s peer review. PLOS staff will follow-up and take action as appropriate. If concerns about peer review integrity are confirmed by PLOS, we may take actions such as reassigning a submission to a different editor, offboarding an editorial board member, excluding a reviewer from peer review, omitting a reviewer’s comments from a decision letter, reporting concerns to the relevant institution(s), and/or editorial action on affected submissions/publications (e.g. rejection, retraction, publication of an editorial notice).

Plagiarism

Plagiarism is not acceptable in PLOS submissions. Plagiarized content will not be considered for publication. If plagiarism is identified, we will follow COPE guidelines.

Plagiarism includes, but is not limited to:

• Directly copying text from other sources without attribution
• Copying ideas, images, or data from other sources without attribution
• Reusing text from your own previous publications without attribution or agreement of the editor (see the COPE guidelines on text recycling and the text recycling guidance released by the Text Recycling Research Project)
  • Exception: Reusing text from the Methods section in the author’s previous publications, with attribution to the source, is acceptable
• Using an idea from another source with slightly modified language without attribution

PLOS uses Crossref Similarity Check (powered by iThenticate) to screen submitted content for originality. Each journal screens a proportion of manuscripts. We will do a follow-up investigation if the software raises any concerns.

If plagiarism is detected during the peer review process, the manuscript may be rejected. If plagiarism is detected after publication, we may issue a correction or retract the paper, as appropriate. We reserve the right to inform authors' institutions about plagiarism detected either before or after publication. 

We expect that editors and reviewers will be vigilant in their evaluation of PLOS submissions and will notify the journal about any plagiarism identified.

Confidentiality

PLOS journals support options by which authors and reviewers can share research early and increase transparency of the peer review process. These include opt-in opportunities to post unpublished work to preprint servers, publish peer review history, and sign names to reviews.

Where options for transparent peer review and/or early sharing are not selected, PLOS protects the confidentiality of unpublished content and the pre-publication peer review process except where needed to support submission checks and integrity investigations (discussed below), to the extent required by law and as otherwise set forth in our privacy policy.

PLOS will follow up on any and all breaches of confidentiality in accordance with COPE guidelines and PLOS policies. If there are special circumstances such that you wish to disclose confidential information about a PLOS submission or its peer review (e.g. to another journal, an institution, or a legal representative), please contact the journal office to discuss the situation and request permission.

Early sharing and public reviews of unpublished work

PLOS encourages and supports early sharing of research via preprint servers. Authors may also, at their discretion, discuss their unpublished research with colleagues or present their unpublished findings (e.g. at conferences) for scientific purposes. When discussing research that has not been accepted for publication with the media, authors should stress that the work is still undergoing peer review, and not disclose the journal where the work is under consideration. See here for additional information. Once accepted and assigned a publication date, all PLOS articles are subject to embargo.

If authors elect to post their PLOS submission on a preprint server, institutional server, or other forum prior to publication, editors and reviewers are welcome to attach their review comments to the preprint if this option is supported by the server. (This does not replace submission of reviews and editors’ comments directly to PLOS via Editorial Manager.)

Confidentiality of unpublished submissions that are not shared on preprint servers

If authors have not elected to share their unpublished work on a public preprint server, the submitted material should be treated as strictly confidential until published.

• We expect that editors and reviewers will not make use of any material or take advantage of any information they gain through the peer review process.
• Editors and reviewers should not share information about unpublished PLOS submissions with anyone who is not directly involved in the submission’s peer review process without explicit permission from PLOS.
• As is stated in our Ethical Peer Review policy, submission content may not be uploaded by handling editors or reviewers to generative AI platforms, websites, databases, or other tools; this is essential for protecting the confidentiality of unpublished work.

Confidentiality and peer review

PLOS requires editors to sign their decision letters, and we list handling editors’ names on PLOS primary research publications, with very rare exceptions.

Reviewers have the option of disclosing their identities to authors by signing their reviews. If reviewers choose not to sign their reviews, PLOS maintains their confidentiality during and after* a manuscript’s/article’s review, and we expect handling editors to do the same. (*See Sharing of unpublished content by PLOS section, below, for exceptions.)

PLOS offers authors the opportunity to publish peer review history (decision letters and reviews) alongside accepted articles. See here for more information. Unpublished peer review details should be held as confidential.

Correspondence as part of the PLOS review process is to be treated confidentially by all parties, including authors. Communications between editorial board members, reviewers, and authors that are related to a PLOS submission’s peer review should be conducted through the journal’s Editorial Manager system.

Sharing of unpublished content by PLOS

PLOS may share unpublished content and other information as outlined in the “How We Use And Disclose Your Information” section of the PLOS Privacy policy.

For example, PLOS may:

• upload unpublished content to web-based tools during submission checks and/or editorial assessments
• share submission contents, author or reviewer information, or peer review information with other trusted publishers, journals, databases, or tools as needed to support integrity checks, publication ethics investigations, and other initiatives aimed at addressing integrity issues
• share submission contents, author or reviewer information, or peer review information with academic research groups and third-party providers of tools or services that help inform improvements to submission checks, peer review, and/or scientific communication
• share unpublished contents (submissions, peer reviews) with institutional officials or other research oversight bodies in the context of publication ethics cases

In sharing unpublished content with third parties or tools we take efforts to protect confidentiality where possible and to mitigate risks to data security.

Anonymity

Reviewers may identify themselves by signing their names at the time reviews are submitted, if they wish.

Submission and Publication of Related Studies

Author requirements

Upon submission of a manuscript, authors must indicate whether there are any related manuscripts under consideration or published elsewhere. If related work has been submitted or published elsewhere, authors must include a copy of it with their submission and describe its relation to the submitted work.

Prior publication of research as a thesis, presentation at medical or scientific conferences, or posting on preprint servers will not preclude consideration of your manuscript.

PLOS supports the public disclosure of all clinical trial results, as mandated, for example, by the 2007 FDA Amendments Act. Prior disclosure of results on a clinical trial registry site will not affect consideration.

Editor and reviewer requirements

Reviewers and editors should evaluate any related content and notify the journal of overlap. Editors and reviewers should alert the journal if they identify duplicate submissions or publications during the review process.

Policy enforcement

If related content is found to be too similar to the PLOS submission, or if a duplicate submission is discovered, we will reject the manuscript.

Duplicate content discovered after publication will be addressed depending on the degree of overlap. The journal may issue a correction or a retraction as appropriate.

Manipulation of the Publication Process

Systematic manipulation of the publication process (sometimes referred to as “paper mill” activity) is defined by COPE as an individual or group of individuals using dishonest or fraudulent practices to

• prevent independent assessment or inappropriately influence peer review outcomes,
• sell or misrepresent authorship, and/or
• publish fabricated or plagiarized research.

Authors should not use any third-party services that offer article content, authorship, or positive peer review outcomes.

Also, authors should not suggest/request handling editors or reviewers with whom there may be a potential competing interest (see here for our Competing Interests policy), and must not interfere with the review process whether directly or via third-party services.

PLOS will reject or retract articles suspected of any manipulation of the publication process, and may inform the relevant institution(s) (e.g. an author’s or reviewer’s employer) of our concerns. In discussing these cases with authors or other parties we may choose not to disclose detailed information about our assessment and specific concerns.

Please email pub-ethics@plos.org if you have concerns about the integrity of a PLOS article’s peer review process, potential paper mill activity involving PLOS content, or other issues involving manipulation of the publication process at PLOS.

Concerns About Data or Figures

When preparing figures, images should not be manipulated or adjusted in any way that could lead to misinterpretation of the information present in the original raw image data. Read more about our guidelines on Preparing Figures from Image Files.

When concerns are raised about reported results, PLOS requests the original underlying data for the experiment(s) in question. If the original data are not available or are not provided in a timely manner, we may take editorial action on the article based on our review of the materials in hand.

We recognize that some institutions and funding agencies only require retention of research data for a finite period after a project’s completion or publication. However, there are no such limits specified within the PLOS Data Availability Policy. Furthermore, in cases involving image issues or other data concerns, the original underlying data are instrumental in clarifying the issues raised and the reliability of the reported results. The unavailability of original data in such cases may impact editorial outcomes.

Artificial Intelligence Tools and Technologies

PLOS expects that articles should report the listed authors’ own work and ideas. Any contributions made by other sources must be clearly and correctly attributed.

Contributions by artificial intelligence (AI) tools and technologies to a study or to an article’s contents must be clearly reported in a dedicated section of the Methods, or in the Acknowledgements section for article types lacking a Methods section. This section should include the name(s) of any tools used, a description of how the authors used the tool(s) and evaluated the validity of the tool’s outputs, and a clear statement of which aspects of the study, article contents, data, or supporting files were affected/generated by AI tool usage.

In cases where Large Language Model (LLM) AI tools or technologies contribute to generating text content for a PLOS submission, the article’s authors are responsible for ensuring that:

• the content is accurate and valid,
• there are no concerns about potential plagiarism,
• all relevant sources are cited, 
• all statements in the article reporting hypotheses, interpretations, results, conclusions, limitations, and implications of the study represent the authors’ own ideas.

The use of AI tools and technologies to fabricate or otherwise misrepresent primary research data is unacceptable.

Noncompliance with any aspect of this policy will be considered misrepresentation of methods, contributions, and/or results. If concerns arise about noncompliance with this policy, PLOS may notify the authors’ institution(s) and the journal may reject (pre-publication), retract (post-publication), or publish an editorial notice on the article.

Biosecurity and Dual Use Research of Concern

PLOS staff and Editorial Boards are committed to the widespread dissemination of research while being sensitive to the issues of responsible publication standards. In this context, we assess the risks and benefits of publishing the research. If the risks outweigh the benefits, we will not publish it.

Author requirements

Authors are obligated to disclose whether the study is subject to consideration as dual use research of concern at the time of submission. Authors should also identify the Institutional Review Entity or equivalent committee(s) granting approval for the study, as well as providing the approval number if one was obtained.

Editor and reviewer requirements

Editors and reviewers are expected to evaluate potential risks and alert the journal with any concerns.

Policy enforcement

We follow standards set by national and public agencies, and may refer concerns to the PLOS Dual Use Committee for an assessment of the potential risks versus benefits of publication.

Manuscripts are checked at submission for any potential risks. Issues identified at submission may lead to rejection of the manuscript.

If risks are identified after publication of an article, we will take steps to minimize that risk in accordance with prevailing guidelines. We may follow up with authors’ institutions depending on the severity of the issues.

Standards for Professional Conduct

PLOS is committed to open scientific communications and professional conduct. We expect that all interactions with PLOS through any medium of communication, including correspondence, calls, posted Comments, and other forms of engagement like social media, will be courteous, respectful, and adherent to high standards of professionalism.

This policy outlines PLOS’ expectations for communications directed towards PLOS staff and/or contributors (authors, editors, reviewers) in the context of PLOS activities, and how PLOS will respond in cases where such expectations are not met.

PLOS will not tolerate any form of harassment or non-professional conduct directed to PLOS staff/contributors in the context of their work for PLOS, such as

• disparaging, insulting, or accusatory ad hominem remarks
• abusive, discriminatory, or hostile language or behavior
• threats targeting an individual
• repeated inquiries to PLOS challenging an editorial outcome, repeated resubmission or complaints after an appeal is declined, or excessive inquiries about an issue that is under investigation

In cases where we are aware that communications/interactions do not meet these expectations, PLOS will take steps as needed to address the situation, which may include one or more of the following:

• providing feedback to the individual(s) involved
• ceasing to engage or communicate on a particular issue
• making changes to the assigned editor/reviewer(s) for a submission

• declining a manuscript without further editorial consideration or peer review
• reviewing or changing an individual’s editorial board status
• seeking support of an individual’s affiliated institution/employer in addressing concerns about that individual’s behavior
• discussing the situation in anonymized form with Committee on Publication Ethics (COPE) representatives or at a COPE forum

Please contact the relevant journal office if you experience interactions or receive verbal or written communications regarding your PLOS work that do not comply with this policy.

Comments posted on third-party sites

If appropriate, PLOS will apply this policy to interactions and comments on third party platforms via its social media channels (Twitter, Facebook and LinkedIn); however, PLOS is not responsible for content posted on third party platforms, and concerns about such content should be escalated via the relevant reporting/complaints process of the host site.

See also the “Impermissible Acts” section of the PLOS Terms of Use.

Research Conducted by PLOS

In our efforts to improve the peer review system and scientific communication, we have an ongoing research program on the processes we use in the course of manuscript handling at the PLOS journals. If you are a reviewer, author or editor at PLOS, and you wish to opt out of this research, please contact the relevant journal office. Participation does not affect the editorial consideration of submitted manuscripts, nor PLOS' policies relating to confidentiality of authors, reviewers or manuscripts.

Individual research projects will be subject to appropriate ethical consideration and approval and if necessary individuals will be contacted for specific consent to participate.