Peer review

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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. Peer review requires a community of experts in a given (and often narrowly defined) field, who are qualified and able to perform 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. Although generally considered essential to academic quality, peer review has been criticized as ineffective, slow, and misunderstood (see anonymous peer review and open peer review).

Pragmatically, peer review refers to the work done during the screening of submitted manuscripts and funding applications. This process encourages authors to meet the accepted standards of their discipline and prevents the dissemination of irrelevant findings, unwarranted claims, unacceptable interpretations, and personal views. Publications that have not undergone peer review are likely to be regarded with suspicion by scholars and professionals.^{[citation needed]}

It is difficult for an individual author or research team to spot every mistake or flaw in a complicated piece of work. This is not necessarily a reflection on the individuals concerned, but because with a new and perhaps eclectic subject, an opportunity for improvement may be more obvious to someone with special expertise or who simply looks at it with a fresh eye. Therefore, showing work to others increases the probability that weaknesses will be identified and improved. For both grant-funding and publication in a scholarly journal, it is also normally a requirement that the subject is both novel and substantial.

Furthermore, the decision whether or not to publish a scholarly article, or what should be modified before publication, lies with the editor of the journal to which the manuscript has been submitted. Similarly, the decision whether or not to fund a proposed project rests with an official of the funding agency. These individuals usually refer to the opinion one or more reviewers in making their decision. This is primarily for three reasons:

• Workload. A small group of editors/assessors cannot devote sufficient time to each of the many articles submitted to many journals.
• Diversity of opinion. Were the editor/assessor to judge all submitted material themselves, approved material would solely reflect their opinion.
• Limited expertise. An editor/assessor cannot be expected to be sufficiently expert in all areas covered by a single journal or funding agency to adequately judge all submitted material.

Thus it is normal for manuscripts and grant proposals to be sent to one or more external reviewers for comment.

Reviewers are typically anonymous and independent, to help foster unvarnished criticism, and to discourage cronyism in funding and publication decisions. However, US government guidelines governing peer review for federal regulatory agencies require that reviewer's identity be disclosed under some circumstances. Anonymity may be unilateral or reciprocal (single- or double-blinded reviewing). There is a perception that scientific evaluation may be more biased in the former case.

Since reviewers are normally selected from experts in the fields discussed in the article, the process of peer review is considered critical to establishing a reliable body of research and knowledge. Scholars reading the published articles can only be expert in a limited area; they rely, to some degree, on the peer-review process to provide reliable and credible research that they can build upon for subsequent or related research. As a result, significant scandal ensues when an author is found to have falsified the research included in an article, as many other scholars, and the field of study itself, may have relied upon the original research (see Peer review and fraud below).

In the case of proposed publications, an editor sends advance copies of an author's work or ideas to researchers or scholars who are experts in the field (known as "referees" or "reviewers"), nowadays normally by e-mail or through a web-based manuscript processing system. Usually, there are two or three referees for a given article.

These referees each return an evaluation of the work to the editor, noting weaknesses or problems along with suggestions for improvement. Typically, most of the referees' comments are eventually seen by the author; scientific journals observe this convention universally. The editor, usually familiar with the field of the manuscript (although typically not in as much depth as the referees, who are specialists), then evaluates the referees' comments, her or his own opinion of the manuscript, and the context of the scope of the journal or level of the book and readership, before passing a decision back to the author(s), usually with the referees' comments.

Referees' evaluations usually include an explicit recommendation of what to do with the manuscript or proposal, often chosen from options provided by the journal or funding agency. Most recommendations are along the lines of the following:

• to unconditionally accept the manuscript or proposal,
• to accept it in the event that its authors improve it in certain ways,
• to reject it, but encourage revision and invite resubmission,
• to reject it outright.

During this process, the role of the referees is advisory, and the editor is typically under no formal obligation to accept the opinions of the referees. Furthermore, in scientific publication, the referees do not act as a group, do not communicate with each other, and typically are not aware of each other's identities or evaluations. There is usually no requirement that the referees achieve consensus. Thus the group dynamics are substantially different from that of a jury.

In situations where the referees disagree substantially about the quality of a work, there are a number of strategies for reaching a decision. When an editor receives very positive and very negative reviews for the same manuscript, the editor often will solicit one or more additional reviews as a tie-breaker. As another strategy in the case of ties, editors may invite authors to reply to a referee's criticisms and permit a compelling rebuttal to break the tie. If an editor does not feel confident to weigh the persuasiveness of a rebuttal, the editor may solicit a response from the referee who made the original criticism. In rare instances, an editor will convey communications back and forth between authors and a referee, in effect allowing them to debate a point. Even in these cases, however, editors do not allow referees to confer with each other, though the reviewer may see earlier comments submitted by other reviewers. The goal of the process is explicitly not to reach consensus or to persuade anyone to change their opinions. Some medical journals, however (usually following the open access model), have begun posting on the Internet the pre-publication history of each individual article, from the original submission to reviewers' reports, authors' comments, and revised manuscripts.

Traditionally, reviewers would remain anonymous to the authors, but this standard is slowly changing. In some academic fields, most journals now offer the reviewer the option of remaining anonymous or not, or a referee may opt to sign a review, thereby relinquishing anonymity. Published papers sometimes contain, in the acknowledgements section, thanks to anonymous or named referees who helped improve the paper.

Some university presses undertake peer review of books. After positive review by two or three independent referees, a university press sends the manuscript to the press's editorial board, a committee of faculty members, for final approval.^[1] Such a review process is a requirement for full membership of the Association of American University Presses.^[2]

In some disciplines there exist refereed venues (such as conferences and workshops). To be admitted to speak, scholars and scientists must submit papers (generally short, often 15 pages or less) in advance. These papers are reviewed by a "program committee" (the equivalent of an editorial board), which generally requests inputs from referees. The hard deadlines set by the conferences tend to limit the options to either accepting or rejecting the paper.

At a journal or book publisher, the task of picking reviewers typically falls to an editor.^[3] When a manuscript arrives, an editor solicits reviews from scholars or other experts who may or may not have already expressed a willingness to referee for that journal or book division. Granting agencies typically recruit a panel or committee of reviewers in advance of the arrival of applications.

Typically referees are not selected from among the authors' close colleagues, students, or friends. Referees are supposed to inform the editor of any conflict of interests that might arise. Journals or individual editors often invite a manuscript's authors to name people whom they consider qualified to referee their work. Indeed, for a number of journals this is a requirement of submission. Authors are sometimes also invited to name natural candidates who should be disqualified, in which case they may be asked to provide justification (typically expressed in terms of conflict of interest). In some disciplines, scholars listed in an "acknowledgements" section are not allowed to serve as referees (hence the occasional practice of using this section to disqualify potentially negative reviewers^{[citation needed]}).

Editors solicit author input in selecting referees because academic writing typically is very specialized. Editors often oversee many specialities, and may not be experts in any of them, since editors may be full time professionals with no time for scholarship. But after an editor selects referees from the pool of candidates, the editor typically is obliged not to disclose the referees' identities to the authors, and in scientific journals, to each other. Policies on such matters differ among academic disciplines.

Recruiting referees is a political art, because referees, and often editors, are usually not paid, and reviewing takes time away from the referee's main activities, such as his or her own research. To the would-be recruiter's advantage, most potential referees are authors themselves, or at least readers, who know that the publication system requires that experts donate their time. Referees also have the opportunity to prevent work that does not meet the standards of the field from being published, which is a position of some responsibility. Editors are at a special advantage in recruiting a scholar when they have overseen the publication of his or her work, or if the scholar is one who hopes to submit manuscripts to that editor's publication in the future. Granting agencies, similarly, tend to seek referees among their present or former grantees. Serving as a referee can even be a condition of a grant, or professional association membership.

Another difficulty that peer-review organizers face is that, with respect to some manuscripts or proposals, there may be few scholars who truly qualify as experts. Such a circumstance often frustrates the goals of reviewer anonymity and the avoidance of conflicts of interest. It also increases the chances that an organizer will not be able to recruit true experts – people who have themselves done work similar to that under review, and who can read between the lines. Low-prestige or local journals and granting agencies that award little money are especially handicapped with regard to recruiting experts.

Finally, anonymity adds to the difficulty in finding reviewers in another way. In scientific circles, credentials and reputation are important, and while being a referee for a prestigious journal is considered an honor, the anonymity restrictions make it impossible to publicly state that one was a referee for a particular article. However, credentials and reputation are principally established by publications, not by refereeing; and in some fields refereeing may not be anonymous.

The process of peer review does not end after a paper completes the peer review process. After being put to press, and after 'the ink is dry', the process of peer review continues in journal clubs. Here groups of colleagues review literature and discuss the value and implications it presents. Journal clubs will often send letters to the editor of a journal, or correspond with the editor via an on-line journal club. In this way, all 'peers' may offer review and critique of published literature.

Peer review can be rigorous, in terms of the skill brought to bear, without being highly stringent. An agency may be flush with money to give away, for example, or a journal may have few impressive manuscripts to choose from, so there may be little incentive for selection. Conversely, when either funds or publication space is limited, peer review may be used to select an extremely small number of proposals or manuscripts.

Often the decision of what counts as "good enough" falls entirely to the editor or organizer of the review. In other cases, referees will each be asked to make the call, with only general guidance from the coordinator on what stringency to apply.

Very general journals such as Science and Nature have extremely stringent standards for publication, and will reject papers that report good quality scientific work if editors feel the work is not a breakthrough in the field. Such journals generally have a two-tier reviewing system. In the first stage, members of the editorial board verify that the paper's findings — if correct — would be ground-breaking enough to warrant publication in Science or Nature. Most papers are rejected at this stage. Papers that do pass this 'pre-reviewing' are sent out for in-depth review to outside referees. Even after all reviewers recommend publication and all reviewer criticisms/suggestions for changes have been met, papers may still be returned to the authors for shortening to meet the journal's length limits. With the advent of electronic journal editions, overflow material may be stored in the journal's online Electronic Supporting Information archive.

A similar emphasis on novelty exists in general area journals such as the Journal of the American Chemical Society (JACS). However, these journals generally send out all papers (except blatantly inappropriate ones) for peer reviewing to multiple reviewers. The reviewers are specifically queried not just on the scientific quality and correctness, but also on whether the findings are of interest to the general area readership (chemists of all disciplines, in the case of JACS) or only to a specialist subgroup. In the latter case, the recommendation is usually for publication in a more specialized journal. The editor may offer to authors the option of having the manuscript and reviews forwarded to such a journal with the same publishers (e.g., in the example given, Journal of Organic Chemistry, Journal of Physical Chemistry, Inorganic Chemistry,...) if the reviewer reports warrant such a decision (i.e., they boil down to "Great work, but too specialized for JACS: publish in ..."), the editor of such a journal may accept the forwarded manuscript without further reviewing.

Specialized scientific journals such as the aforementioned chemistry journals, Astrophysical Journal, and the Physical Review series use peer review primarily to filter out obvious mistakes and incompetence, as well as plagiarism, overly derivative work, and straightforward applications of known methods. Different publication rates reflect these different criteria: Nature publishes about 5 percent of received papers, while Astrophysical Journal publishes about 70 percent. Some open access journals such as Biology Direct have the policy of making the reviewers' reports public by publishing the reports together with the manuscripts.

Screening by peers may be more or less laissez-faire depending on the discipline. Physicists, for example, tend to think that decisions about the worthiness of an article are best left to the marketplace. Yet even within such a culture peer review serves to ensure high standards in what is published. Outright errors are detected and authors receive both edits and suggestions.

To preserve the integrity of the peer-review process, submitting authors may not be informed of who reviews their papers; sometimes, they might not even know the identity of the associate editor who is responsible for the paper. In many cases, alternatively called "masked" or "double-masked" review (or "blind" or "double-blind" review), the identity of the authors is concealed from the reviewers, lest the knowledge of authorship bias their review; in such cases, however, the associate editor responsible for the paper does know who the author is. Sometimes the scenario where the reviewers do know who the authors are is called "single-masked" to distinguish it from the "double-masked" process. In double-masked review, the authors are required to remove any reference that may point to them as the authors of the paper.

While the anonymity of reviewers is almost universally preserved, double-masked review (where authors are also anonymous to reviewers) is still relatively rarely employed.

Critics of the double-masked process point out that, despite the extra editorial effort to ensure anonymity, the process often fails to do so, since certain approaches, methods, writing styles, notations, etc., may point to a certain group of people in a research stream, and even to a particular person.^[4][5] Proponents of double-masked review argue that it performs at least as well as the traditional one and that it generates a better perception of fairness and equality in global scientific funding and publishing.^[6]

Proponents of the double-masked process argue that if the reviewers of a paper are unknown to each other, the associate editor responsible for the paper can easily verify the objectivity of the reviews. Single-masked review is thus strongly dependent upon the goodwill of the participants.

A conflict of interest arises when a reviewer and author have a disproportionate amount of respect (or disrespect) for each other. As an alternative to single-masked and double-masked review, authors and reviewers are encouraged to declare their conflicts of interest when the names of authors and sometimes reviewers are known to the other. When conflicts are reported, the conflicting reviewer is prohibited from reviewing and discussing the manuscript. The incentive for reviewers to declare their conflicts of interest is a matter of professional ethics and individual integrity. While their reviews are not public, these reviews are a matter of record and the reviewer's credibility depends upon how they represent themselves among their peers. Some software engineering journals, such as the IEEE Transactions on Software Engineering, use non-blind reviews with reporting to editors of conflicts of interest by both authors and reviewers.

A more rigorous standard of accountability is known as an audit. Because reviewers are not paid, they cannot be expected to put as much time and effort into a review as an audit requires. Most journals (and grant agencies like NSF) have a policy that authors must archive their data and methods in the event another researcher wishes to replicate or audit the research after publication^{[citation needed]}. Unfortunately, the archiving policies are sometimes ignored by researchers.

One of the most common complaints about the peer review process is that it is slow, and that it typically takes several months or even several years in some fields for a submitted paper to appear in print. In practice, much of the communication about new results in some fields such as astronomy no longer takes place through peer-reviewed papers, but rather through preprints submitted onto electronic servers such as arXiv.org. However, such preprints are often also submitted to refereed journals, and in many cases have, at the time of electronic submission, already passed through the peer review process and been accepted for publication.

While passing the peer-review process is often considered in the scientific community to be a certification of validity, it is not without its problems. Drummond Rennie, deputy editor of Journal of the American Medical Association is an organizer of the International Congress on Peer Review and Biomedical Publication, which has been held every four years since 1986.^[7] He remarks, "There seems to be no study too fragmented, no hypothesis too trivial, no literature too biased or too egotistical, no design too warped, no methodology too bungled, no presentation of results too inaccurate, too obscure, and too contradictory, no analysis too self-serving, no argument too circular, no conclusions too trifling or too unjustified, and no grammar and syntax too offensive for a paper to end up in print."^[8]

Richard Horton, editor of the British medical journal The Lancet, has said that "The mistake, of course, is to have thought that peer review was any more than a crude means of discovering the acceptability — not the validity — of a new finding. Editors and scientists alike insist on the pivotal importance of peer review. We portray peer review to the public as a quasi-sacred process that helps to make science our most objective truth teller. But we know that the system of peer review is biased, unjust, unaccountable, incomplete, easily fixed, often insulting, usually ignorant, occasionally foolish, and frequently wrong." ^[9]

The interposition of editors and reviewers between authors and readers always raises the possibility that the intermediators may serve as gatekeepers. Some sociologists of science argue that peer review makes the ability to publish susceptible to control by elites and to personal jealousy.^[10] The peer review process may suppress dissent against "mainstream" theories.^[11][12][13] Reviewers tend to be especially critical of conclusions that contradict their own views, and lenient towards those that accord with them. At the same time, elite scientists are more likely than less established ones to be sought out as referees, particularly by high-prestige journals or publishers. As a result, it has been argued, ideas that harmonize with the elite's are more likely to see print and to appear in premier journals than are iconoclastic or revolutionary ones, which accords with Thomas Kuhn's well-known observations regarding scientific revolutions.^[14]

Others have pointed out that there is a very large number of scientific journals in which one can publish, making total control of information difficult. In addition, the decision-making process of peer review, in which each referee gives their opinion separately and without consultation with the other referees, is intended to mitigate some of these problems. Some have suggested that:

"... peer review does not thwart new ideas. Journal editors and the 'scientific establishment' are not hostile to new discoveries. Science thrives on discovery and scientific journals compete to publish new breakthroughs."^[15]

Peer review failures occur when a peer-reviewed article contains obvious fundamental errors that undermines at least one of its main conclusions. Peer review is not considered a failure in cases of deliberate fraud by authors. Many journals have no procedure to deal with peer review failures beyond publishing letters to the editor.^[16]

Peer review, in scientific journals, assumes that the article reviewed has been honestly written, and the process is not designed to detect fraud. The reviewers usually do not have full access to the data from which the paper has been written and some elements have to be taken on trust. It is not usually practical for the reviewer to reproduce the author's work. Publication of incorrect results does not in itself indicate a peer review failure.

It has been suggested that traditional anonymous peer review lacks accountability, can lead to abuse by reviewers, and may be biased and inconsistent,^[17] alongside other flaws.^[18][19] In response to these criticisms, other systems of peer review with various degrees of "openness" have been suggested.

Starting in the 1990s, several scientific journals (including the high impact journal Nature in 2006) started experiments with hybrid peer review processes, often allowing open peer reviews in parallel to the traditional model. The initial evidence of the effect of open peer review upon the quality of reviews, the tone and the time spent on reviewing was mixed, although it does seem that under open peer review, more of those who are invited to review decline to do so.^[20][21]

Throughout the 2000s first academic journals based solely on the concept of open peer review were launched (see e.g. Philica). An extension of peer review beyond the date of publication is Open Peer Commentary, whereby expert commentaries are solicited on published articles, and the authors are encouraged to respond.

The technique of peer review is also used to improve government policy. In particular, the European Union uses it as a tool in the 'Open Method of Co-ordination' of policies in the fields of employment and social inclusion.

A programme of peer reviews in active labour market policy^[22] started in 1999, and was followed in 2004 by one in social inclusion.^[23] Each programme sponsors about eight peer review meetings in each year, in which a 'host country' lays a given policy or initiative open to examination by half a dozen other countries and relevant European-level NGOs. These usually meet over two days and include visits to local sites where the policy can be seen in operation. The meeting is preceded by the compilation of an expert report on which participating 'peer countries' submit comments. The results are published on the web.

The first recorded peer review process was at The Royal Society in 1665 by the founding editor of Philosophical Transactions of the Royal Society, Henry Oldenburg.^[24][25]

According to the common definition of a peer review, the first peer review was 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.^[26]

A practice similar to a peer review process is found in the Ethics of the Physician written by Ishaq bin Ali al-Rahwi (854–931) of al-Raha, Syria. His work, as well as later Arabic medical manuals, state that a visiting physician must always make duplicate notes of a patient's condition on every visit. When the patient was cured or had died, the notes of the physician were examined by a local medical council of other physicians, who would review the practising physician's notes to decide whether his/her performance have met the required standards of medical care. If their reviews were negative, the practicing physician could face a lawsuit from a maltreated patient.^[27]

Peer review has been a touchstone of modern scientific method only since the middle of the 20th century, the only exception being medicine. Before then, its application was lax in other scientific fields. For example, Albert Einstein's revolutionary "Annus Mirabilis" papers in the 1905 issue of Annalen der Physik were not peer-reviewed by anyone other than the journal's editor in chief, Max Planck (the father of quantum theory), and its co-editor, Wilhelm Wien. Although clearly peers (both won Nobel prizes in physics), a formal panel of reviewers was not sought, as is done for many scientific journals today. Established authors and editors were given more latitude in their journalistic discretion, back then. In a recent editorial in Nature, it was stated that "in journals in those days, the burden of proof was generally on the opponents rather than the proponents of new ideas."^[28]

• Academic conference
• Academic journal
• Abstract management
• Adversarial review
• Cudos
• Journal Club
• Objectivity
• Open Peer Commentary
• Publication bias
• Scholarly method
• Sham peer review
• Sokal affair
• Sternberg peer review controversy

This article has an unclear citation style. The references used may be made clearer with a different or consistent style of citation and footnoting. (Learn how and when to remove this message)

• Ann C. Weller Editorial Peer Review: its Strengths and Weaknesses Medford, NJ: American Society for Information Science and Technology, 2001. ISBN 1573871001 (extensive bibliography)

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• Nature peer review debate June 2006
• Fifth International Congress on Peer Review and Biomedical Publication
• Discussion forum about the peer review system
• "A Difficult Balance: Editorial Peer Review in Medicine" (Bibliography, hosted by Eugene Garfield)

• Beyond Open Access: Open Discourse, the next great equalizer, (Retrovirology 2006, 3:55)
• The Maharishi Caper: Or How to Hoodwink Top Medical Journals, The Newsletter of the National Association of Science Writers
• "Measuring the quality of peer review" Journal of the American Medical Association 287: 2786–2790 (2002).
• Peer review – process, perspectives and the path ahead (J Postgrad Med 2001;47:210-4)
• Something Rotten at the Core of Science? (Analysis of US court decision of criteria for scientific evidence)
• Malice's Wonderland: Research Funding and Peer Review (Journal of Neurobiology 14, No. 2., pp. 95-112 (1983). ()
• Is agreement between reviewers any greater than would be expected by chance alone? (Brain, Vol. 123, No. 9, 1964-1969, September 2000)
• Science and Politics: An Uneasy Mix (Reprinted from GSA Today, v. 14, no. 7 (July 2004))
• The philosophical basis of peer review and the suppression of innovation (JAMA. 1990 March 9;263(10):1438-41. and comment JAMA. 1990 December 26;264(24):3143.)
• Suppressing Dissent in Science (Lancet Volume 357, Number 9257 3 March 2001)
• Hampering the progress of science by peer review and by the 'selective' funding system (Science Tribune - Article - December 1996 )
• Suppression of Dissent in Science (Research in Social Problems and Public Policy V. 7)
• Refereed Journals: Do They Insure Quality or Enforce Orthodoxy? Frank J. Tipler, and discussion board.
• The peer-review system: time for re-assessment? (Marine Ecology Progress Series)
• Philip E. Bourne, Alon Korngreen, "Ten Simple Rules for Reviewers", PLoS Computational Biology, 2(9):e110, 2006 September. General guidelines for reviewing.
• Stevan Harnad:
  • 1998: The Invisible Hand of Peer Review Nature version; Exploit Interactive version
  • 1997: Learned Inquiry and the Net: The Role of Peer Review, Peer Commentary and Copyright (Learned Publishing 11(4) pp. 283-292.)
  • 1996: Implementing Peer Review on the Net: Scientific Quality Control in Scholarly Electronic Journals (Peek, R. and Newby, G., Eds. , pp. 103-118. MIT Press.)
  • 1985: Rational disagreement in peer review (Science, Technology and Human Values 10 pp. 55-62.)
  • 1979: Creative disagreement (The Sciences 19 18 - 20.)
  • 1978 Behavioral and Brain Sciences (BBS) editorial
• The Task of the Referee
• A web-based survey on the practice of peer-review in political science: The Political Science Peer-Review Survey