Double blind review, also called double anonymous peer review, is a model in which the identities of authors and reviewers are concealed from one another during manuscript evaluation.
The journal normally removes or asks authors to remove identifying information before the manuscript is sent to reviewers.
Authors may need to anonymize elements such as:
The objective is to encourage reviewers to assess the research primarily on its scientific content.
Double blind review is one model within the broader peer review process rather than a completely different form of scientific evaluation.
Three broad models are commonly discussed.
Single Blind Review. In single blind review, reviewers usually know who the authors are, but authors do not know the identities of the reviewers.
Supporters argue that reviewer anonymity allows experts to provide candid criticism without concern about professional consequences.
However, knowledge of author identity may potentially influence reviewer expectations.
Double Blind Review. In double blind review, neither side knows the other's identity during the review.
The intended benefit is to reduce biases related to author characteristics.
The main limitation is practical: true anonymity is difficult to maintain, particularly in small research fields.
Open Peer Review. Open peer review can refer to several models, but commonly involves revealing reviewer identities, publishing reviewer reports, revealing author-reviewer interactions, or some combination of these approaches.
Supporters argue that openness increases transparency and accountability.
Critics note that identifiable reviewers may become less willing to provide strong criticism, especially when reviewing work by senior or influential researchers.
No model eliminates every source of bias or error.
The primary rationale for double blind review is reducing reviewer bias unrelated to the scientific content of the manuscript.
Author identity can provide signals about:
These factors should not determine whether a scientific argument is valid, yet they can influence expectations.
An anonymous manuscript may make it more difficult for a reviewer to assume that research is strong simply because it comes from a prestigious institution.
The reverse also applies. Reviewers may be less likely to undervalue work because it comes from an unfamiliar institution, early-career researcher, or less prominent research group.
Double blind review cannot remove biases arising from the paper itself, including preferences for particular theories, methods, topics, or types of results.