Five C's of Ethics for Peer Review in Scientific Publishing

June 2, 2023

Scientific publishing and academic advancement of ideas rely heavily on the process of peer review. Most scholarly publishers, like ASM, provide guidelines for peer review to editors and reviewers participating in this process. While conversation continues in the field regarding the merits of different peer review methods (e.g., single-blinded, double-blinded, triple-blinded or open-peer review), one thing is certain, ethical guidelines, such as those recommended by the Committee on Publication Ethics (COPE), will always be applicable and imperative to maintain the integrity of the highly trusted peer review process. The 5 C’s of ethical peer review listed below take a broad view to lay the foundation for this process.
  1. Conflict of Interest. 
  2. Confidentiality.
  3. Credit.
  4. Constructive Criticism.
  5. Courtesy.

Conflict of Interest

The graphic shows the 5C's of ethics in the peer review process.
The 5 C's governing an ethical peer review process for the various stakeholders, including authors, reviewers and editors.
Source: American Society for Microbiology
A fair and impartial review is possible only when it is free from any competing interests and conscious or unconscious biases. When editors and reviewers receive a request to review a manuscript, they usually reveal the more obvious conflicts of interest, like affiliations with the same institutes, or previous significant collaborations with the authors. Similarly, intellectual or financial conflicts of interest that may affect the outcome of a review should be revealed before agreeing to review a manuscript. That said, often it may be hard to identify what constitutes such conflicts, in which case communicating them to the journal's staff is a good first step. For example, a reviewer might suggest the authors cite articles authored by the reviewer in their manuscript. A request like this to improve one's own citation statistics for personal gain (monetary or otherwise, e.g., with the intent to return similar favors in the future) is not an acceptable request and is an ethics violation.

To maintain trust in and integrity of scientific publishing in the global era—where scientific knowledge is shareable, accessible and comes from diverse backgrounds—it is imperative to identify conflicting biases (conscious or unconscious) that one may have as an editor or reviewer. Such biases may come from one’s own favorable or opposing views on the study under review. Other factors that could impact the outcome of a review include the country of origin of the corresponding author, the type of institutional affiliation or the gender and/or race of the corresponding author. With only 14% of editors being comprised of women, there is a large gender gap in scientific publishing, which further creates a less diverse pool of reviewers being requested and authors being published. Although ASM journals have a higher percentage (~28.8%) of women editors, women are still underrepresented at all levels of the peer review process, and manuscripts submitted by women corresponding authors receive more negative outcomes.


Authors entrust the journals, editors and reviewers to maintain the confidentiality of their unpublished work while it is under consideration. Until the manuscript is published, its content should not be disclosed, discussed, shared or commented upon. Such confidentiality is necessary to maintain the integrity of the system. COPE designed systems to safeguard an author against any misconduct or breach of reviewer confidentiality, such as misuse of unpublished content to progress a reviewer's own research. Furthermore, permission from the journal is required to include another individual, e.g., post-doctoral researchers or graduate students whom a reviewer is mentoring, in the review process.


To that end, journals have systems in place to provide credit to the individual devoting their time to perform a review and contribute to scientific publishing. However, early career researchers may miss receiving credit for their role as a co-reviewer because the journals are unaware of their contribution, often referred to as the practice of ghostwriting a review. Mentored co-reviewing is designed to fill this need and increase transparency of the peer review process by additionally giving credit to early career reviewers participating in this process. At ASM, Microbiology Spectrum's Reviewer Editor Program and mBio's Early Career Reviewer Program are mentoring programs that provide training and hands-on experience for peer reviewing manuscripts to early career scientists. Eventually, a new pool of independent, trained peer reviewers is created and maintained to uphold the ethical values and credibility of this system for the future.

Constructive Criticism

Ethical peer review requires reviewers to pay attention to the 5 C's: conflict of interest, confidentiality, credit, constructive criticism and courtesy.
Disclosing all conflict of interest, maintaining confidentiality, attributing proper credit to all reviewers, providing constructive criticism and displaying courtesy are key components of ethical peer review.
Source: iStock
Peer review assesses the science behind the research study and manuscript. By sharing their unbiased, honest critiques on the strengths and weaknesses of the work, reviewers and editors improve the quality of the publication. Therefore, providing constructive criticism is crucial for the survival and growth of scientific publishing. Intentionally rejecting the work of a competitor by supplying unfair negative comments or requesting unjustified experiments or explanations to harm the outcome of the review process, is considered unethical. If the work has major weaknesses, reviewers should provide helpful suggestions and make it clear how the authors can improve their manuscript for publication.


It is the responsibility of a reviewer to deliver a fair, honest and unbiased assessment of the strengths and weaknesses of the manuscript to the authors. Reviewers should not include ad hominem or unprofessional comments, and editors can edit them out. The thoroughness and consistency of reviews supplied to the author and editor can further support decision-making by the editors. Respectfully providing feedback and noting if the manuscript may benefit from edits regarding overall flow, grammar, etc. is important to improve overall clarity. This further allows for a more comprehensive review of the study's scientific merit and scope. ASM provides links to copy-editing services as well as language editing services that authors may find useful. This trust in the ethical conduct of the review process creates a space where diversity, equity and inclusion have a voice and can coexist. 

Emerging Challenges to Ethical Peer Review

The traditional peer review system has guidelines that inform reviewers of their ethical obligations to this process. However, as the world begins to understand and cautiously accept the evolving landscape of artificial intelligence (AI) in various aspects of scientific writing, it presents new ethical challenges in peer review and scholarly publishing. The effectiveness of digital tools in facilitating review, and which automated tool performs better when it comes to screening or reviewing preprints and manuscripts, remain to be seen. Nevertheless, these tools cannot replace the valuable experience and knowledge of human reviewers and editors to genuinely and thoroughly assess the work of authors and their peers. For example, the ability of AI to determine more complex aspects of a study, such as accurate use of an experiment to test a hypothesis, is not on par with human decision-making. Therefore, relying on AI to assess the implications of a study on current trends and future models in the field presents a large ethical dilemma. 

Publishers have increased efforts in detecting plagiarism in manuscript texts by incorporating CrossChecks and detecting potential image manipulation by pre-screening manuscripts before publication. These proactive measures ensure focus on publishing high-quality content that can be trusted by the community at large. As reported in the 2019 Peer Review Survey conducted by Elsevier, in partnership with Sense About Science, researcher satisfaction in the process of peer review has increased, and researchers acknowledge that peer review improves the quality of the published work. The survey also found that more reviewers want to be recognized for their work, which presents new perspectives when discussing the future models and frameworks of the peer review system. Although the current system has room for improvement, these findings underscore the need to comprehend the peer review process better. Increased awareness and better appreciation of reviewer responsibilities can certainly pave an ethical path forward.
Aashi Chaturvedi, Ph.D., the author of this article, will be speaking about "Navigating the Complexities of Scientific Ethics," at ASM Microbe 2023 on June 18, 2023 from 10:45-11:30 a.m. 

Author: Aashi Chaturvedi, Ph.D.

Aashi Chaturvedi, Ph.D.
Aashi Chaturvedi, Ph.D., is the Senior Ethics Specialist at the American Society for Microbiology.