This FAQ is a lightly-edited and slightly extended version of Mike Hicks' double-blind reviewing FAQ from POPL 2012.
Q: Why are you using double-blind reviewing?
A: Our goal is to give each a reviewer an unbiased "first look" at each paper. Studies have shown that a reviewer's attitude toward a submission may be affected, even unconsciously, by the identity of the author (see link below to more details). We want reviewers to be able to approach each submission without such involuntary reactions as "Barnaby; he writes a good paper" or "Who are these people? I have never heard of them." For this reason, we ask that authors to omit their names from their submissions, and that they avoid revealing their identity through citation. Note that many systems and security conferences use double-blind reviewing and have done so for years (e.g., SIGCOMM, OSDI, IEEE Security and Privacy, SIGMOD). POPL and PLDI have done it for the last several years.
A key principle to keep in mind is that we intend this process to be cooperative, not adversarial. If a reviewer does discover an author's identity though a subtle clue or oversight the author will not be penalized.
For those wanting more information, see the list of studies about gender bias in other fields and links to CS-related articles that cover this and other forms of bias below.
Q: Do you really think blinding actually works? I suspect reviewers can often guess who the authors are anyway.
A: Studies of blinding with the flavor we are using show that author identities remain unknown 53% to 79% of the time (see Snodgrass, linked below, for details). Moreover, about 5-10% of the time (again, see Snodgrass), a reviewer is certain of the authors, but then turns out to be at least partially mistaken. So, while sometimes authorship can be guessed correctly, the question is, is imperfect blinding better than no blinding at all? If author names are not explicitly in front of the reviewer on the front page, does that help at all even for the remaining submissions where it would be possible to guess? Our conjecture is that on balance the answer is "yes".
Q: Couldn't blind submission create an injustice where a paper is inappropriately rejected based upon supposedly-prior work which was actually by the same authors and not previously published?
A: I have heard of this happening, and this is indeed a serious issue. In the approach we are taking for POPL'15, author names are revealed to reviewers after they have submitted their review. Therefore, a reviewer can correct their review if they indeed have penalized the authors inappropriately. Unblinding prior to the PC meeting also avoids abuses in which committee members end up advancing the cause of a paper with which they have a conflict.
Q: What happens if the Program Chair has a conflict with the authors of a submitted paper?
A: Sriram Rajamani, POPL 2015 General Chair, has agreed to help manage the reviewing process for papers with which the Program Chair has a conflict.
A: Your job is not to make your identity undiscoverable but simply to make it possible for our reviewers to evaluate your submission without having to know who you are. The specific guidelines stated in the call for papers are simple: omit authors' names from your title page (or list them as "omitted for submission"), and when you cite your own work, refer to it in the third person. For example, if your name is Smith and you have worked on amphibious type systems, instead of saying "We extend our earlier work on statically typed toads (Smith 2004)," you might say "We extend Smith's (2004) earlier work on statically typed toads." Also, be sure not to include any acknowledgements that would give away your identity. If you have any questions, feel free to ask the PC chair.
Q: I would like to provide supplementary material for consideration, e.g., the code of my implementation or proofs of theorems. How do I do this?
A: On the submission site there will be an option to submit supplementary material along with your main paper. This supplementary material need not be anonymized; it will only be revealed to reviewers after they have submitted their review of your paper and learned your identity. Reviewers are under no obligation to look at this material. The submission itself is the object of review and so it should strive to convince the reader of at least the plausibility of reported results; supplemental material only serves to confirm, in more detail, the idea argued in the paper. Of course, reviewers are free to change their review upon viewing supplemental material (or for any other reason). For those authors who wish to supplement, we encourage them to mention the supplement in the body of the paper so reviewers know to look for it, if necessary. E.g., "The proof of Lemma 1 is included in the non-anonymous supplemental material submitted with this paper."
Q: Is there a way for me to submit anonymous supplemental material which could be considered by a reviewer before she submits her review (rather than potentially non-anonymous material that can only be viewed afterward) ?
A: There is no official channel for doing this: the submission site only accepts potentially non-anonymous material. That said, authors have been known to release a TR, code, etc. via an anonymous hosting service, and to include a URL to that material in the paper. However, we discourage authors from using such tactics except for materials that cannot, for some reason, be uploaded to the official site (e.g., a live demo). We emphasize that authors should strive to make their paper as convincing as possible within the submission page limit, in case reviewers choose not to access supplemental material. Also, see the next question.
Q: Can I supplement my submission using a URL that links to auxiliary materials instead of submitting such materials to the HotCRP system directly?
A In general, we discourage authors from providing supplementary materials via links to external web sites. It is possible to change the linked items after the submission deadline has passed, and, to be fair to all authors, we would like to be sure reviewers evaluate materials that have been completed prior to the submission deadline. Having said that, it is appropriate to link to items, such as an online demo, that can't easily be submitted. Needless to say, attempting to discover the reviewers for your paper by tracking visitors to such a demo site would be a breach of academic integrity. Supplementary items such as PDFs should always be uploaded to HotCRP.
Q: I am building on my own past work on the WizWoz system. Do I need to rename this system in my paper for purposes of anonymity, so as to remove the implied connection between my authorship of past work on this system and my present submission?
A: No. The relationship between systems and authors changes over time, so there will be at least some doubt about authorship. Increasing this doubt by changing the system name would help with anonymity, but it would compromise the research process. In particular, changing the name requires explaining a lot about the system again because you can't just refer to the existing papers, which use the proper name. Not citing these papers runs the risk of the reviewers who know about the existing system thinking you are replicating earlier work. It is also confusing for the reviewers to read about the paper under Name X and then have the name be changed to Name Y. Will all the reviewers go and re-read the final version with the correct name? If not, they have the wrong name in their heads, which could be harmful in the long run.
Q: I am submitting a paper that extends my own work that previously appeared at a workshop. Should I anonymize any reference to that prior work?
A: No. But we recommend you do not use the same title for your POPL submission, so that it is clearly distinguished from the prior paper. In general there is rarely a good reason to anonymize a citation. One possibility is for work that is tightly related to the present submission and is also under review. But such works may often be non-anonymous. When in doubt, contact the PC Chair.
Q: Am I allowed to post my (non-blinded) paper on my web page? Can I advertise the unblinded version of my paper on mailing lists or send it to colleagues? May I give a talk about my work while it is under review?
A: As far as the authors' publicity actions are concerned, a paper under double-blind review is largely the same as a paper under regular (single-blind) review. Double-blind reviewing should not hinder the usual communication of results.
That said, we do ask that you not attempt to deliberately subvert the double-blind reviewing process by announcing the names of the authors of your paper to the potential reviewers of your paper. It is difficult to define exactly what counts as "subversion" here, but a blatant example might include sending individual e-mail to members of the PC or ERC about your work (unless they are conflicted out anyway). On the other hand, it is perfectly fine, for example, to visit other institutions and give talks about your work, to present your submitted work during job interviews, to present your work at professional meetings (e.g. Dagstuhl), or to post your work on your web page. In general, PC/ERC members will not be asked to recuse themselves if they discover the (likely) identity of an author through such means. If you're not sure about what constitutes "subversion", please consult directly with the Program Chair.
Q: Will the fact that POPL is double-blind have an impact on handling conflicts-of interest? When I am asked by the submission system to identify conflicts of interest, what criteria should I use?
A: Using DBR does not change the principle that reviewers should not review papers with which they have a conflict of interest, even if they do not immediately know who the authors are. Quoting (with slight alteration) from the ACM SIGPLAN review policies document:
A conflict of interest is defined as a situation in which the reviewer can be viewed as being able to benefit personally in the process of reviewing a paper. For example, if a reviewer is considering a paper written by a member of his own group, a current student, his advisor, or a group that he is seen as being in close competition with, then the outcome of the review process can have direct benefit to the reviewer's own status. If a conflict of interest exists, the potential reviewer should decline to review the paper.As an author, you should list PC and ERC members (and any others, since others may be asked for outside reviewers) which you believe have a conflict with you. While particular criteria for making this determination may vary, please apply the following guidelines, identifying a potential reviewer Bob as conflicted if
If a possible reviewer does not meet the above criteria, please do not identify him/her as conflicted. Doing so could be viewed as an attempt to prevent a qualified, but possibly skeptical reviewer from reviewing your paper. If you nevertheless believe that a reviewer who does not meet the above criteria is conflicted, you may identify the person and send a note to the PC Chair.
Q: What should I do if I if I learn the authors' identity? What should I do if a prospective POPL author contacts me and asks to visit my institution?
A: If at any point you feel that the authors' actions are largely aimed at ensuring that potential reviewers know their identity, you should contact the Program Chair. Otherwise you should not treat double-blind reviewing differently from regular blind reviewing. In particular, you should refrain from seeking out information on the authors' identity, but if you discover it accidentally this will not automatically disqualify you as a reviewer. Use your best judgment.
Q: The authors have provided a URL to supplemental material. I would like to see the material but I worry they will snoop my IP address and learn my identity. What should I do?
A: Contact the Program Chair, who will download the material on your behalf and make it available to you.
Q: If I am assigned a paper for which I feel I am not an expert, how do I seek an outside review?
A: PC and ERC members should do their own reviews, not delegate them to someone else. If doing so is problematic for some papers, e.g., you don't feel completely qualified, then consider the following options. First, submit a review for your paper that is as careful as possible, outlining areas where you think your knowledge is lacking. Assuming we have sufficient expert reviews, that could be the end of it: non-expert reviews are valuable too, since conference attendees are by-and-large not experts for any given paper. Second, if you feel like the gaps in your knowledge are substantial, submit a first cut review, and then work with the PC chair to solicit an external review. This is easy: after submitting your review the paper is unblinded, so you at least know not to solicit the authors! You will also know other reviewers of the paper that have already been solicited. If none of these expert reviewers is acceptable to you, just check with the PC Chair that the person you do wish to solicit is not conflicted with the authors. In addition, the PC chair will attempt to balance the load on external reviewers. Keep in mind that while we would like the PC to make as informed a decision as possible about each submitted paper, each additional review we solicit places a burden on the community.
As a last resort, if you feel like your review would be extremely uninformed and you'd rather not even submit a first cut, contact the PC Chair, and another reviewer will be assigned.
Q: May I ask one of my students to do a review for me?
A: Having students (or interns at a research lab) participate in the review process is good for their education. However, you should not just "offload" your reviews to your students. Each review assigned to you is your responsibility. We recommend the following process: If you are sure that your student's conflicts of interest are a subset of your own, you and your student may both begin to do your own separate reviews in parallel. (A student's review should never simply be a substitute for your own work.) If your student's conflicts of interest are not a subset of your own, you may do your own first-cut review first and then unblind the authors so you can check, or you may consult with the PC chair. Either way, once the student has completed their review, you should check the review to ensure the tone is professional and the content is appropriate. Then you may merge the student's review with your own.
Q: How do we handle potential conflicts of interest since I cannot see the author names?
A: The conference review system will ask that you identify conflicts of interest when you get an account on the submission system. Please see the related question applied to authors to decide how to identify conflicts. Feel free to also identify additional authors whose papers you feel you could not review fairly for reasons other than those given (e.g., strong personal friendship).
Q: Are PC members allowed to submit papers? If so, how are they handled?
A: PC members are allowed to submit papers. All such papers will be reviewed by the POPL 2015 ERC (not other PC members). This makes for a more comfortable PC meeting and, at the same time, may act to remove the appearance of bias of PC members towards their colleagues' papers. When ERC members are evaluating a PC paper, they should do so as if it is any other paper, ignoring the fact that a PC member is an author. However, since SIGPLAN mandates that PC member papers be held to a "higher standard," if at the end of the process, ERC members are deadlocked concerning a particular PC paper, that paper will not receive the benefit of the doubt, whereas a regular non-PC paper might.
Q: Are ERC members allowed to submit papers? If so, how are they handled?
A: ERC members are allowed to submit papers. Their papers will be reviewed like any other paper. There is no "higher standard" for ERC papers.
Q: How should I handle a paper I feel is very good, and yet would be a better fit for PLDI (or ICFP or OOPSLA)?
A: The scope of POPL is broad and encompasses all topics that pertain to programming language theory, design and implementation. Hence, if you feel a paper would be an excellent PLDI (or ICFP or OOPSLA) paper then it would also be an excellent POPL paper. To be accepted at POPL, a paper must discuss programming languages in some way, shape or form and it must have the potential to make a lasting impact on our field.
Q: How should I handle a paper that is out of scope for POPL?
A: The scope of POPL is broad and encompasses all topics that pertain to programming language theory, design and implementation. However, if you discover you have been assigned a paper that does not contribute to the study of programming languages, please contact the program chair. We will discuss it and may decide to reject the paper on grounds of scope. Of course, if we decide after all that the paper is within the scope of POPL, you should review it like any other paper.
Note that this information was put together by the program chair; not all program or external review committee members are necessarily persuaded by it.
Kathryn McKinley's editorial makes the case for double-blind reviewing from a computer science perspective. Her article cites Richard Snodgrass's SIGMOD record editorial which collects many studies of the effects of potential bias in peer review.
Here are a few studies on the potential effects of bias manifesting in a merit review process, focusing on bias against women. (These were collected by David Wagner.)
Snodgrass' studies includes some of these, and more.