What Is Peer Review?

Peer review is a process in which independent experts in a field evaluate a piece of research before it is published, usually in an academic journal or as a conference paper or book. The reviewers, who are the author's peers, assess whether the methods are sound, the evidence supports the conclusions and the work makes a worthwhile contribution. It is one of the main quality checks in scholarly publishing.

How it works

1. Submission: the authors send a manuscript to a journal.
2. Editor check: an editor decides whether it fits the journal and is worth sending out for review.
3. Review: the editor invites typically two or three experts to read it and write reports, recommending that it be accepted, revised or rejected.
4. Decision: the editor weighs the reports and decides. Many papers are returned for revision.
5. Revision: the authors respond to comments and improve the paper, often through several rounds.
6. Publication: if accepted, the paper is published.

Types of peer review

• Single-blind: reviewers know the authors' names, but the authors do not know who reviewed.
• Double-blind: neither side knows the other's identity, to reduce bias.
• Open review: identities, and sometimes reports, are made public.
• Post-publication review: comments and critiques after publication, sometimes alongside preprints.

Strengths and limits

Peer review helps to catch errors, improve clarity and filter out weak work. It is not perfect. Reviewers are usually unpaid and busy, may share the biases of their field and can miss mistakes or fraud. Some journals have weak or no real review, which is a feature of predatory publishing. Studies that have passed review can still be retracted later.

Using it as a student

Lecturers often ask you to use peer-reviewed sources because they have been checked by experts. To make sure that your source qualifies:

• Use library databases with a filter for peer-reviewed or scholarly journals.
• Check the journal's website for its review policy.
• Distinguish article types: original research and review articles are normally reviewed, while editorials and letters may not be.
• Be careful with preprints, which have not been reviewed.
• Read critically, even when a source is peer reviewed.

Why it matters

Peer review is the reason why academic sources carry more weight than blogs and news articles in most assignments. Understanding how it works helps you judge evidence and talk about the quality of studies.

Related terms

See scholarly journal, preprint, impact factor, open access and primary source.