Guidelines for Reviewers
“We are sincerely grateful to scholars who give their time to peer-review articles submitted to MDPI journals. Rigorous peer-review is the corner-stone of high quality academic publishing.”
— The MDPI editorial team.
Find a journal in your field
- Benefits of MDPI Volunteer Reviewers
- Invitation to Join MDPI Volunteer Reviewer Database
- Invitation to Review
- Potential Conflicts of Interests
- Confidentiality and Anonymity
- Timely Review Reports
- Peer-Review and Editorial Procedure
- Rating the Manuscript
- Overall Recommendation
- Review Report
- MDPI Review Reports Sharing
- Guidelines for Reviewers for Registered Reports Papers
- Guideline for Reviewers for Collaborative Peer Review
- Guideline for Reviewers for Depositing Review Activities into ORCID
Peer review is an essential part in the publication process, ensuring that MDPI maintains high quality standards for its published papers. Reviewing is often an unseen and unrewarded task. We are striving to recognize the efforts of reviewers.
When reviewing for MDPI journals you:
- Receive a discount voucher code entitling you to a reduction in the article processing charge (APC) of a future submission to any MDPI journal. Vouchers are linked to your email address and can be applied online at submission or any time before acceptance. Note that vouchers cannot be used after an invoice has been issued. If your article is rejected the voucher can be reused for your next submission.
- Receive a personalized reviewer certificate.
- Are included in the journal’s annual acknowledgment of reviewers.
- Are considered for the journal’s outstanding reviewer award.
- Can build your profile on Publons and have your reviewing activity automatically added for participating journals. Publons profiles can also be integrated with ORCID.
If you are interested in reviewing articles for one or more of our journals, please register your contact details, including your ORCID identifier, institutional affiliation, a short CV, and 5-6 keywords in line with your expertise at the following page.
The managing editors of the selected journals will send you a notification once approved.
Prospective reviewers may also be interested in the Publons Academy, which provides training in how to conduct peer review.
Manuscripts submitted to MDPI journals are reviewed by at least two experts. Reviewers are asked to evaluate the quality of the manuscript and to provide a recommendation to the external editor on whether a manuscript can be accepted, requires revisions or should be rejected.
We ask invited reviewers to:
- accept or decline any invitations quickly, based on the manuscript title and abstract;
- suggest alternative reviewers if an invitation must be declined;
- request an extension in case more time is required to compose a report;
- let us know if anyone else, such as a student, will participate in writing the review.
- to rate the originality, significance, quality of the presentation, scientific soundness, interest to the readers, overall merit and English level of the manuscript;
- to look at the reference list of the manuscript and check if there are inappropriate self-citations;
- to provide an overall recommendation for the publication of the manuscript;
- to provide a detailed, constructive review report;
We ask reviewers to inform the journal editor if they hold a conflict of interests that may prejudice the review report, either in a positive or negative way. The editorial office will check as far as possible before invitation, however we appreciate the cooperation of reviewers in this matter. Reviewers who are invited to assess a manuscript they previously reviewed for another journal should not consider this as a conflict of interest in itself. In this case, reviewers should feel free to let us know if the manuscript has been improved or not compared to the previous version.
Reviewers should keep the content of the manuscript, including the abstract, confidential. Reviewers must inform the Editorial Office if they would like a student or colleague to complete the review on their behalf.
MDPI journals operate single or double blind peer review. Reviewers should be careful not to reveal their identity to the authors, either in their comments or in metadata for reports submitted in Microsoft Word or PDF format.
MDPI journals offer authors the possibility to publish review reports with their paper and for reviewers to sign their open review reports, however this will only be done at publication with your express permission. If this is the case, it will be noted in the message inviting you to review. In all other cases, review reports are considered confidential and will only be disclosed with the explicit permission of the reviewer.
Note that, as the reviewer, you will have access to other reviewers' reports via the online submission system after you have submitted your report.
MDPI aims to provide an efficient and high quality publishing service to authors and to the scientific community. We ask reviewers to assist by providing review reports in a timely manner. Please contact the editorial office if you require an extension to the review deadline.
All manuscripts sent for publication in our journals are strictly and thoroughly peer-reviewed by experts (this includes research and review articles, spontaneous submissions, and invited papers). The Managing Editor of the journal will perform an initial check of the manuscript’s suitability upon receipt. The Editorial Office will then organize the peer-review process performed by independent experts and collect at least two review reports per manuscript. We ask our authors for adequate revisions (with a second round of peer-review if necessary) before a final decision is made. The final decision is made by the academic editor (usually the Editor-in-Chief/Editorial Board Member of a journal or the Guest Editor of a Special Issue). Accepted articles are copy-edited and English-edited.
Please rate the following aspects of the manuscript:
- Originality/Novelty: Is the question original and well defined? Do the results provide an advance in current knowledge?
- Significance: Are the results interpreted appropriately? Are they significant? Are all conclusions justified and supported by the results? Are hypotheses and speculations carefully identified as such?
- Quality of Presentation: Is the article written in an appropriate way? Are the data and analyses presented appropriately? Are the highest standards for presentation of the results used?
- Scientific Soundness: is the study correctly designed and technically sound? Are the analyses performed with the highest technical standards? Are the data robust enough to draw the conclusions? Are the methods, tools, software, and reagents described with sufficient details to allow another researcher to reproduce the results?
- Interest to the Readers: Are the conclusions interesting for the readership of the Journal? Will the paper attract a wide readership, or be of interest only to a limited number of people? (please see the Aims and Scope of the journal)
- Overall Merit: Is there an overall benefit to publishing this work? Does the work provide an advance towards the current knowledge? Do the authors have addressed an important long-standing question with smart experiments?
- English Level: Is the English language appropriate and understandable?
- Manuscripts should only report results that have not been submitted or published before, even in part.
- Manuscripts must be original and should not reuse text from another source without appropriate citation.
- For biological studies, the studies reported should have been carried out in accordance with generally accepted ethical research standards.
If reviewers become aware of such scientific misconduct or fraud, plagiarism or any other unethical behavior related to the manuscript, they should raise these concerns with the in-house editor immediately.
Please provide an overall recommendation for the publication of the manuscript as follows:
Accept in Present Form: The paper is accepted without any further changes.
Accept after Minor Revisions: The paper is in principle accepted after revision based on the reviewer’s comments. Authors are given five days for minor revisions.
Reconsider after Major Revisions: The acceptance of the manuscript would depend on the revisions. The author needs to provide a point by point response or provide a rebuttal if some of the reviewer’s comments cannot be revised. Usually, only one round of major revisions is allowed. Authors will be asked to resubmit the revised paper within ten days and the revised version will be returned to the reviewer for further comments.
Reject: The article has serious flaws, makes no original contribution, and the paper is rejected with no offer of resubmission to the journal.
Note that your recommendation is visible only to journal editors, not to the authors.
We have listed some general instructions regarding the review report for your consideration. Please find these below.
To begin with, please consider the following guidelines:
- Read the whole article as well as the supplementary material, if there is any, paying close attention to the figures, tables, data and methods.
- Your report should critically analyze the article as a whole but also specific sections and the key concepts presented in the article.
- Please ensure your comments are detailed so that the authors may better understand and address the points you raise.
- Reviewers must not recommend excessive citation of their work (self-citations), another author’s work (honorary citations) or articles from the journal where the manuscript was submitted as a means of increasing the citations of the reviewer/authors/journal. You can provide references as needed, but they must clearly improve the quality of the manuscript under review.
- Please maintain a neutral tone and focus on providing constructive criticism that will help the authors improve their work. Derogatory comments will not be tolerated.
Note that MDPI journals follow several standards and guidelines, including those from the ICMJE (medical journals), CONSORT (trial reporting), TOP (data transparency and openness), PRISMA (systematic reviews and meta-analyses) and ARRIVE (reporting of in vivo experiments). See the Publishing Standards and Guidelines page or contact the editorial office for more details. Reviewers that are familiar with the guidelines should report any concerns they have about their implementation.
For further guidance on writing a critical review, please refer to the following documents:
- COPE Ethical Guidelines for Peer Reviewers. Committee on Publication Ethics. Available online.
- Hames, I. Peer Review and Manuscript Management in Scientific Journals: Guidelines for Good Practice. Wiley-Blackwell: Oxford, UK, 2007.
- Writing a journal article review. Australian National University: Canberra, Australia, 2010. Available online.
- Golash-Boza, T. How to write a peer review for an academic journal: Six steps from start to finish. Available online.
Review reports should contain the following:
- A brief summary (one short paragraph) outlining the aim of the paper, its main contributions and strengths.
General concept comments
Article: highlighting areas of weakness, the testability of the hypothesis, methodological inaccuracies, missing controls, etc.
Review: commenting on the completeness of the review topic covered, the relevance of the review topic, the gap in knowledge identified, the appropriateness of references, etc.
These comments are focused on the scientific content of the manuscript and should be specific enough for the authors to be able to respond.
- Specific comments referring to line numbers, tables or figures that point out inaccuracies within the text or sentences that are unclear. These comments should also focus on the scientific content and not on spelling, formatting or English language problems, as these can be addressed at a later stage by our internal staff.
General questions to help guide your review report for research articles
- Is the manuscript clear, relevant for the field and presented in a well-structured manner?
- Are the cited references current (mostly within the last 5 years)? Does it include an abnormal number of self-citations?
- Is the manuscript scientifically sound and is the experimental design appropriate to test the hypothesis?
- Are the manuscript’s results reproducible based on the details given in the methods section?
- Are the figures/tables/images/schemes appropriate? Do they properly show the data? Are they easy to interpret and understand? Are the data interpreted appropriately and consistently throughout the manuscript? Please include details regarding the statistical analysis or data acquired from specific databases.
- Are the conclusions consistent with the evidence and arguments presented?
- Please evaluate the ethics statements and data availability statements to ensure they are adequate.
General questions to help guide your review report for review articles
- Is the review clear, comprehensive and of relevance to the field? Is a gap in knowledge identified?
- Was a similar review published recently and, if yes, is this current review still relevant and of interest to the scientific community?
- Are the cited references current (mostly within the last 5 years)? Are any citations omitted? Does it include an abnormal number of self-citations?
- Are the statements and conclusions drawn coherent and supported by the listed citations?
- Are the figures/tables/images/schemes appropriate? Do they properly show the data? Are they easy to interpret and understand?
Reviewers may suggest that a manuscript may be more appropriate for publication in another MDPI journal. To save time and effort, authors would have the possibility to request the transfer of review reports to another MDPI journal. The full list of journals published by MDPI can be found here.
The review process for Registered Reports is divided into two stages. In Stage 1, reviewers assess study proposals before data is collected. In Stage 2, reviewers consider the full study, including results and interpretation.
When reviewing Stage 1 papers, note that no experimental data or results will be included. You only need to assess the method, including, for example:
- The importance and soundness of the proposed hypotheses
- The suitabilty and feasibility of the experimental and analysis methodology
- Whether there are sufficient details given to replicate the proposed experimental procedures and analysis
- Whether there are sufficient outcome-neutral tests of the hypotheses, including positive controls and quality checks
Manuscripts that pass Stage 1 peer review maybe published immediately or after the successful completion of Stage 2 (at the authors’ discretion). Editorial decisions will not be based on the importance or novelty of the results.
For Stage 2 manuscripts, reviewers will be asked to appraise:
- Whether the data are able to test the original proposed hypotheses by satisfying the approved outcome-neutral conditions (such as quality checks, positive controls)
- Whether the stated hypotheses tested was the same as the approved Stage 1 submission
- Whether the authors adhered precisely to the registered experimental procedures or were able to sufficiently justify any changes
- Whether any new analyses (not mentioned at Stage 1) are methodologically sound and relevant
- Whether the authors’ conclusions are justified given the data
Collaborative Peer Review consists of two phases:
- Reviewers assess the manuscript independently and finish the review report form.
- Before authors complete revisions, to reach a consensus and ensure subsequent process is smoother for everyone (the authors clearly understand how to revise their paper), author could raise queries to reviewers if they do not understand or disagree with some of comments. However, this not a mandatory step for authors. The authors could skip it and make revisions directly. Reviewers reply to authors and provide a clear description of what they need to do to advance to publication.
MDPI provides a service for depositing review activities into ORCID iD if the reviewer’s ORCID account is connected to the MDPI Submission System account. You are able to register an account and connect your ORCID here (https://susy.mdpi.com/user/edit). Once the accounts are connected, you could deposit your review records manually here (https://susy.mdpi.com/user/reviewer/status/finished).