Scholarly peer review (also known as refereeing) is the process of subjecting an author's scholarly work, research, or ideas to the scrutiny of others who are experts in the same field, before a paper describing this work is published in a journal or as a book. The peer review helps the publisher (that is, the editor-in-chief or the editorial board) decide whether the work should be accepted, considered acceptable with revisions, or rejected. Peer review requires a community of experts in a given (and often narrowly defined) field, who are qualified and able to perform reasonably impartial review. Impartial review, especially of work in less narrowly defined or inter-disciplinary fields, may be difficult to accomplish, and the significance (good or bad) of an idea may never be widely appreciated among its contemporaries. Peer review is generally considered necessary to academic quality and is used in most major scientific journals, but does by no means prevent publication of all invalid research. Traditionally, peer reviewers have been anonymous, but there is currently a significant amount of open peer review, where the comments are visible to readers, generally with the identities of the peer reviewers disclosed as well.
The first record of an editorial pre-publication peer-review is from 1665 by Henry Oldenburg, the founding editor of Philosophical Transactions of the Royal Society at the Royal Society of London.
The first peer-reviewed publication might have been the Medical Essays and Observations published by the Royal Society of Edinburgh in 1731. The present-day peer-review system evolved from this 18th-century process, began to involve external reviewers in the mid-19th-century, and did not become commonplace until the mid-20th-century.
Peer review became a touchstone of the scientific method, but until the end of the 19th century only an editor-in-chief or editorial committees performed it.