I have received a review request from a journal (in case it matters, it is the best journal in a certain field of mathematics). The article has some material in which I can reasonably be considered an expert (because I myself have published something related in the same journal) whereas some other aspect of the article is beyond my comfort zone.

Therefore, I am thinking of responding to the request affirmatively under the provision that there is some other reviewer who can better review the latter aspect of the paper. My question for this site is whether or not if this is a common and/or acceptable reply to a review request.

A related issue is that the Web editorial system is set up so that a comment to the editor is solicited only if a review request is declined. I'm not sure if I want to decline the request solely to talk to the editor and cost the authors a few more weeks of administrative time.

  • 2
    I have never done a review where I was the sole reviewer, but I am not in mathematics. Is it common in mathematics to have only one reviewer to make such a request necessary?
    – Sursula
    Commented May 29, 2023 at 13:49
  • 5
    @Sursula (reputable) journals won't want to have only one reviewer, but it sometimes happens that the editor can only find one suitable person who is willing to review. (Reviewing an article in mathematics is a lot of work relative to other areas, because of the difficulty of checking correctness.) Probably the prestige of the journal will affect how long they are willing to spend looking for a second reviewer. Commented May 29, 2023 at 13:59
  • 15
    Except at the very top journals, papers in mathematics are usually reviewed by only one person. Commented May 29, 2023 at 16:09
  • This situation happens from time to time in math, and my suggestion is email the editor to discuss this. See also point 4 of academia.stackexchange.com/a/131593/19607
    – Kimball
    Commented May 31, 2023 at 22:28

6 Answers 6


It's not very common, but does happen that a paper is reviewed by several referees where each only read one part of it. (I've been on the other end of it - being asked if I could review "at least part" of a certain particularly long paper.) It is definitely a reasonable offer on the part of the referee. I'm assuming that the there's an invite email signed by an editor; I would contact them by e-mail before clicking "accept" in the system.

That said, there's a case to accept the entire refereeing task without any provisions.

  • being an expert on half the content of the paper, you are as qualified a reader as it gets. If you cannot understand and check the validity of the second part, arguably the authors should rewrite it so it is understandable to you.
  • it may be very beneficial for you to learn in-depth new material that is directly connected to what you are doing. Some of us have an amazing self-discipline but for others having an external deadline helps :)

This request isn't common, sufficiently so that I've yet to see it after handling hundreds of reviews.

It is relatively common that referees says "I'm not an expert on X, but I'm an expert on Y, and ...". In this case most editors will look for an expert on X. If this involves inviting reviewers anew, then so be it - you gotta do what you gotta do. It's conceivable that reviewers say "I'm not an expert on X" while accepting the review request - if there's a box for such comments they might use that, otherwise they can just reply to the invitation email and reach someone who will know what to do. I don't recall seeing this happen, but it'd surely be appreciated, since it tells the editor to start looking for a reviewer who knows X now instead of after you submit your review.

What is most unusual about your request is that you are accepting on condition you are not the only reviewer, which makes it seem like you think you are in charge of the paper. You're not the editor, you don't make final decisions, and editors can accept/reject a paper which you recommend reject/accept for (see e.g. this question). But it's a common misconception, so something a long-time editor is unlikely to bat an eyelid at.

tl; dr:

  • No, it's not common.
  • Yes, it's acceptable.
  • Reply to the invitation email and tell them you lack expertise in X. Odds are they'll say "in that case, let's cancel" or "that's not a problem, review anyway". In the latter situation, you can expect that they will look for someone with expertise in X.
  • 10
    I don’t see how the condition makes it seem like the asker thinks they’re in charge of the paper. They’re simply saying that if the journal cannot or will not find a second reviewer (preferably one who knows about X, of course), then they will decline the request to act as reviewer. There’s no mention of any final decisions anywhere. Commented May 30, 2023 at 8:57
  • 1
    @JanusBahsJacquet I get the same impression as Allure. Second guessing the motivation for such an unusual request, the first reason that came to my mind is that the asker doesn't want to be held solely responsible if their review on parts where they are not an expert misled the editor's decision and thus potentially do injustice to the author of the paper. So, by "in charge", I see it as "I'm the only reviewer responsible for this paper's fate".
    – justhalf
    Commented May 30, 2023 at 13:05
  • 4
    @justhalf That’s how I read the question as well – but that’s a far cry from thinking that you’re the editor or make the final decisions. Commented May 30, 2023 at 13:24
  • Comments have been moved to chat; please do not continue the discussion here. Before posting a comment below this one, please review the purposes of comments. Comments that do not request clarification or suggest improvements usually belong as an answer, on Academia Meta, or in Academia Chat. Comments continuing discussion may be removed.
    – Bryan Krause
    Commented May 30, 2023 at 20:27
  • Are you in pure mathematics? I have both told an editor I can only referee a certain part of a paper in detail (who said fine), and also been requested by an editor to just review one part of a paper.
    – Kimball
    Commented May 31, 2023 at 22:26

I don't understand. Full disclosure, I've reviewed 2 papers (I'm still a student). And I don't care if I'm the only person they ask to review, I care about if I can give valuable feedback to the paper.

If you don't feel like you can, then just tell the editor "Hey I know I can review some of this, but I'm not sure if I'd know about X Y Z". In fact, even just from personal experience: second paper I've reviewed, I basically reviewed their methods. I was the "methods" reviewer, if you will. Most of my focus commented on their implementation. The other two focused more on the substantive area of things, while additionally commenting on methods. So, it's not completely unheard of.

My point is, different reviewers will bring different strengths. Also, the managing editor will also have their feedback to give based on yours, so it won't (usually) just literally be you doing the reviewing. Either way, make your concerns known from jump.

  • 2
    I feel like the sentence "I care about if I can give valuable feedback to the paper" shows that you miss an important part of your role as a reviewer. You have to be able to judge the scientific value of the work. You might have valuable feedback without being able to make this judgement. In that case you should not review the paper. Whether being an expert on one part of the paper is enough to make this judgement or not will depend entirely on the paper.
    – Kvothe
    Commented May 30, 2023 at 13:38
  • I don't agree with you (that I'm missing the point, that is). To me, being able to give valuable feedback is predicated on you being able to judge the scientific quality of the manuscript. Of course, I do spellchecking and proofreading while reviewing, but to me, critically engaging with the science and its implications is of chief importance. Whenever I've agreed to review, I briefly looked at the manuscript and asked myself "Okay, is this something I should be commenting on, am I the right reviewer for this?" @Kvothe But overall, I agree with you. Commented May 30, 2023 at 15:51

I see this as a common issue and have seen this with myself being Reviewer 1, Reviewer 2, as well as Editor

  • Reviewer 1 writes to Editor (following review request): I can review the paper but have never worked with Piffles and thus will not be able to comment on the applications concerning Piffles in section 3.

  • Editor replies: Thank you. Yes, that is fine, please do so and I will find another reviewer for this part. [ The editor could say: No, thank you, I want you to review the whole paper, but they would be foolish to insist on this unless both parts are deeply interwoven, as they will need to find another willing reviewer. ]

  • Editor writes to prospective reviewer 2: I received this paper that proves an interesting result in Q-Theory. They apply this to a question on Piffles, which is an area that this ont well known within the Q-theory community. This argument is localized in section 3. I am asking you, being an expert on Piffles, whether you could comment on the validity of and potential interest in this material in this section.

  • Reviewer 2 replies to Editor: I will do so, but restrict my review on section 3 and take the Q-theory statement (Theorem 17) as true.

As Reviewer 1 you will not know who reviewer 2 is, nor what they will do in detail. There is nothing formally written down concerning the restricted role, apart from the reply from the Editor.

Ultimately it is the Editor's responsibility to ensure that the paper is fully covered.


I have done a similar thing myself a couple of times. No, it’s not common. Yes, it’s acceptable. However, I would (and did, when I was in this situation) phrase things differently, and specifically I would leave out the part where you set conditions to the editor for accepting the assignment - as others have commented, that’s overstepping your role and comes across as a bit entitled.

Instead, just state that you can only provide feedback pertaining to the part of the paper you have expertise on (and explain what that part is). The editor can determine whether that suits their needs. And you can trust that the editor can think of the idea of getting another reviewer without you making that specific suggestion (let alone phrasing it as a demand).


You could just tell them you're not expert for certain aspects and then leave the decision what to do about this to the editor. Normally they will find another reviewer, but they also may have enough personal expertise to assess the missing part themselves. Or your review for the part you know about turns out to be so bad that the other part can't save the paper anyway.

As an editor I am very keen on reviewers who acknowledge their limitations, but I wouldn't like a condition as you suggest, because I may not yet have another reviewer at the time point when you're asking for this, and not be able to guarantee that I'll find one in limited time. So my advice is: Just accept the task, say clearly what you are not expert for, and leave the further responsibility to the editor.

Re your other question: Can you maybe find a contact email address in the email that invited you to review? Do you know who the editor is and find their email on the web? If I remember correctly, I have always found a way to contact the editor/journal when I needed to, and declaring a lack of competence for a part of the paper is a good reason to do this.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .