Peer Review

What is "peer review"?

At its core, peer review (or the process called "referreeing") is the effort of scholars within a similar discipline or area of research to critique and evaluate the scholarly contribution from others within that same domain, and determine whether that scholarship should be disseminated or how it can be improved. Peer review results in over 1.5 million scholarly articles published each year.

Journals differ in the percentage of submitted papers that they accept and reject. Higher impact factor journals such as Science or Nature can reject even good quality research papers if an editor deems it not ground-breaking enough. Other journals, such as PLoS One, instead take the approach of getting more scholarship out and circulated. They have utilized a review process that focuses on satisfaction of scientific rigors rather than assesment of innovativeness.


Basic Models for Peer Review

As scholarly publishing changes, so too have peer review models. Typically, though, peer review involves authors (who conduct research and write the manuscript), reviewers ("peers" in the domain who provide expert opinions and advice), and editors (who make acceptance and publishing decisions). A basic model could like like the following, though there are multiple approaches:

Sample Peer Review Process courtesy Taylor & Francis

In this model: A paper is submitted to a journal. A journal editor screens the manuscript to determine whether it should be passed through to the critque stage, or rejected outright. The editor collects reviewers who then undertake analysis and critique of the work. The reviewers pass opinions and suggested edits back to the editor, who asks the author to revise accodingly. This process of revision could go through several iterations. After author revisions are complete, the editor will decide whether to accept the paper for publication, or reject it.

Note, too, that some publishers have implemented a "cascading" approach so as not to squander reviewers' efforts if a paper is ultimately rejected by an editor at the final stage. As Dan Morgan, Digital Science Publisher at the University of California Press, explains (at p. 10 of the Standing up for Science 3 guide to peer review):

Cascading peer review (a.k.a. 'waterfall peer review') is when a paper that has been rejected after peer review is passed on to another journal along with the reviewers' reports. The peer review process at the second journal can be kept relatively short because the editor considers the reports from an earlier round of peer review, along with any new reviews. Variations on this process exist, according to the type of journal - but essentially reviews can 'cascade' down through various journals.

Cascading peer review can accelerate the time to publication so that valuable review efforts are not lost. Moreover, many publishing groups that issue multiple journals will automatically apply this process--helping to find the right journal for your particular manuscript.



Within this basic peer review model, journals can employ different approaches to how and whether authors get to know their reviewers, and vice versa. The idea behind masking or revealing this information is that such knowledge may introduce bias, or affect how honest and critical the reviews are. These various approaches include, for example:

  • Single-blind review: Reviewers know who authors are, but authors do not know know who reviewers are. 
  • Double-blind review: Neither reviewers nor authors are informed about who the others are.
  • Open review: Reviewers and authors know who each other are, and this review can also include the transmission of reviewer commentary in the open final publication.
  • Post-publication open review: Here, readers and reviewers can submit public comments on published articles. Often, these comments are mediated by the editor.

If working papers are uploaded to a repository (such as ArXiv for mathematics, physics, and non-life sciences), there is also an opportunity for pre-publication peer review via the comments submitted by readers and downloaders at those sites.


Learn more

You can learn a lot more about the mechanics of peer review, and tips for how to conduct peer review, in the following guides:

And you can contact with questions at