Starting in March, Nature and the monthly Nature research journals will offer an alternative to conventional peer review. Authors will be able to request that their names and affiliations are withheld from reviewers of their papers — a form of peer review known as double blind. At present, the process is single blind: reviewers are anonymous, but they know the authors’ identities.

Alternatives to the conventional peer-review process are often proposed. Some have suggested fully open reviews, in which the names of both authors and reviewers are known. Proponents of open peer review see its transparency as a way to encourage more civil and thoughtful reviewer comments — although others are concerned that it promotes a less critical attitude.

By contrast, advocates of double-blind peer review suggest that it eliminates personal biases, such as those based on gender, seniority, reputation and affiliation.

Both systems are already in use across scholarly publishing, but there is no consensus on which is best. Nature experimented with open peer review in 2006, but at the time, despite expressed interest, the uptake from both authors and reviewers was low and the open reviews were not technically substantive. Views about open peer review are probably still evolving as several journals continue to experiment with variations on this practice. Opinions about double-blind review, however, are remarkably consistent.

In one of the largest studies on peer review — a 2009 inter­national and cross-disciplinary survey of more than 4,000 researchers — 76% of respondents indicated that double blind was an effective peer-review system (A. Mulligan, L. Hall and E. Raphael J. Am. Soc. Inf. Sci. Technol. 64, 132–161; 2013). (By comparison, open and single-blind peer review were considered effective by 20% and 45% of respondents, respectively.) Our own surveys confirm that double-blind peer review is a popular option. Importantly, this sentiment is widely echoed in conversations that our editors have had with young scientists worldwide. These conversations demonstrate a widespread perception that biases based on authorship affect single-blind peer review.

The decision to offer double-blind review has been much discussed. Editors of Nature journals have previously resisted it for several reasons. Some were sceptical of its efficacy, some were concerned about the potential difficulty of recruiting referees, and some still saw it as their responsibility to mitigate the biases that this method tackles.

All editors take this responsibility seriously and will continue to select reviewers carefully and consider their comments. They will also continue to honour reasonable requests from authors to exclude particular reviewers, regardless of the chosen method of peer review. But by definition, unconscious biases may be difficult to identify and to control. Several studies have detected involuntary biases, notably based on gender, in other areas of the scientific enterprise, such as in the hiring of laboratory staff, citation habits and speaker line-ups at conferences.

Since June 2013, Nature Geoscience and Nature Climate Change have allowed authors to choose between double-blind and single-blind peer review at submission. The uptake of the double-blind method has been much lower than the enthusiasm expressed in surveys suggested it would be. No more than one-fifth of monthly submissions to these journals are choosing the double-blind route. No substantial effects on the quality of reviews have been detected. The positive reactions to the trial from surveyed authors are a big part in the decision to start offering double-blind review at Nature and the Nature monthly journals as well. (Nature Communications will join later.)

How will it work? The responsibility to render the manuscript anonymous falls to the authors. Clearly, keeping their identities from reviewers will not always be possible, especially in small and specialist fields. We also continue to promote policies that support researchers who wish to release data early and to discuss their work with their peers before publication, through conferences or by posting research on preprint servers. These routes to publication also compromise anonymity. That is why the double-blind process is optional on all titles. We expect that some authors will choose it because of concern about biases, others purely on principle.

We will keep this initiative under review, and we, of course, welcome comments from authors and reviewers.