How to Write a Peer Review

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When you write a peer review for a manuscript, what should you include in your comments? What should you leave out? And how should the review be formatted? This guide provides quick tips for writing and organizing your reviewer report.

Review Outline

Use an outline for your reviewer report so it’s easy for the editors and author to follow. This will also help you keep your comments organized.

Think about structuring your review like an inverted pyramid. Put the most important information at the top, followed by details and examples in the center, and any additional points at the very bottom.

Graphic of upside down pyramid representing a peer review outline

Here’s how your outline might look:

1. Summary of the research and your overall impression

In your own words, summarize what the manuscript claims to report. This shows the editor how you interpreted the manuscript and will highlight any major differences in perspective between you and the other reviewers. Give an overview of the manuscript’s strengths and weaknesses. Think about this as your “take-home” message for the editors. End this section with your recommended course of action.

2. Discussion of specific areas for improvement

It’s helpful to divide this section into two parts: one for major issues and one for minor issues. Within each section, you can talk about the biggest issues first or go systematically figure-by-figure or claim-by-claim. Number each item so that your points are easy to follow (this will also make it easier for the authors to respond to each point). Refer to specific lines, pages, sections, or figure and table numbers so the authors (and editors) know exactly what you’re talking about.

Major vs. minor issues

What’s the difference between a major and minor issue? Major issues should consist of the essential points the authors need to address before the manuscript can proceed. Make sure you focus on what is fundamental for the current study. In other words, it’s not helpful to recommend additional work that would be considered the “next step” in the study. Minor issues are still important but typically will not affect the overall conclusions of the manuscript. Here are some examples of what would might go in the “minor” category:

  • Missing references (but depending on what is missing, this could also be a major issue)
  • Technical clarifications (e.g., the authors should clarify how a reagent works)
  • Data presentation (e.g., the authors should present p-values differently)
  • Typos, spelling, grammar, and phrasing issues

3. Any other points

Confidential comments for the editors

Some journals have a space for reviewers to enter confidential comments about the manuscript. Use this space to mention concerns about the submission that you’d want the editors to consider before sharing your feedback with the authors, such as concerns about ethical guidelines or language quality. Any serious issues should be raised directly and immediately with the journal as well.

This section is also where you will disclose any potentially competing interests, and mention whether you’re willing to look at a revised version of the manuscript.

Do not use this space to critique the manuscript, since comments entered here will not be passed along to the authors. If you’re not sure what should go in the confidential comments, read the reviewer instructions or check with the journal first before submitting your review. If you are reviewing for a journal that does not offer a space for confidential comments, consider writing to the editorial office directly with your concerns.

Giving Feedback

Giving feedback is hard. Giving effective feedback can be even more challenging. Remember that your ultimate goal is to discuss what the authors would need to do in order to qualify for publication. The point is not to nitpick every piece of the manuscript. Your focus should be on providing constructive and critical feedback that the authors can use to improve their study.

If you’ve ever had your own work reviewed, you already know that it’s not always easy to receive feedback. Follow the golden rule: Write the type of review you’d want to receive if you were the author. Even if you decide not to identify yourself in the review, you should write comments that you would be comfortable signing your name to.

In your comments, use phrases like “the authors’ discussion of X” instead of “your discussion of X.” This will depersonalize the feedback and keep the focus on the manuscript instead of the authors.

General guidelines for effective feedback

Don’t…

  • Recommend additional experiments or  unnecessary elements that are out of scope for the study or for the journal criteria.
  • Tell the authors exactly how to revise their manuscript—you don’t need to do their work for them.
  • Use the review to promote your own research or hypotheses.
  • Focus on typos and grammar. If the manuscript needs significant editing for language and writing quality, just mention this in your comments.
  • Submit your review without proofreading it and checking everything one more time.
Do…

  • Justify your recommendation with concrete evidence and specific examples.
  • Be specific so the authors know what they need to do to improve.
  • Be thorough. This might be the only time you read the manuscript.
  • Be professional and respectful. The authors will be reading these comments too.
  • Remember to say what you liked about the manuscript!

Before and After: Sample Reviewer Comments

Keeping in mind the guidelines above, how do you put your thoughts into words? Here are some sample “before” and “after” reviewer comments.

Before

After


✗ “The authors appear to have no idea what they are talking about. I don’t think they have read any of the literature on this topic.”

✓ “The study fails to address how the findings relate to previous research in this area. The authors should rewrite their Introduction and Discussion to reference the related literature, especially recently published work such as Darwin et al.”


✗ “The writing is so bad, it is practically unreadable. I could barely bring myself to finish it.”

✓ “While the study appears to be sound, the language is unclear, making it difficult to follow. I advise the authors work with a writing coach or copyeditor to improve the flow and readability of the text.”


✗ “It’s obvious that this type of experiment should have been included. I have no idea why the authors didn’t use it. This is a big mistake.”

✓ “The authors are off to a good start, however, this study requires additional experiments, particularly [type of experiment]. Alternatively, the authors should include more information that clarifies and justifies their choice of methods.”

Suggested Language for Tricky Situations

You might find yourself in a situation where you’re not sure how to explain the problem or provide feedback in a constructive and respectful way. Here is some suggested language for common issues you might experience.

What you think: The manuscript is fatally flawed.
What you could say: “The study does not appear to be sound” or “the authors have missed something crucial”.

What you think: You don’t completely understand the manuscript.
What you could say: “The authors should clarify the following sections to avoid confusion…”

What you think: The technical details don’t make sense.
What you could say: “The technical details should be expanded and clarified to ensure that readers understand exactly what the researchers studied.”

What you think: The writing is terrible.
What you could say: “The authors should revise the language to improve readability.”

What you think: The authors have over-interpreted the findings.
What you could say: “The authors aim to demonstrate [XYZ], however, the data does not fully support this conclusion. Specifically…”

What does a good review look like?

Check out the peer review examples at F1000 Research to see how other reviewers write up their reports and give constructive feedback to authors.

Time to Submit the Review!

Be sure you turn in your report on time. Need an extension? Tell the journal so that they know what to expect. If you need a lot of extra time, the journal might need to contact other reviewers or notify the author about the delay.

Tip: Building a relationship with an editor

You’ll be more likely to be asked to review again if you provide high-quality feedback and if you turn in the review on time. Especially if it’s your first review for a journal, it’s important to show that you are reliable. Prove yourself once and you’ll get asked to review again!