Policy for signed comments

For manuscripts that replicate earlier research, directly challenge earlier work or directly build on such work, we invite the authors of the original work to provide signed comments. This policy applies to both research and non-research manuscripts. 

Signed comments must be:

• Limited strictly to methodological issues and the accuracy with which the work is represented in the target manuscript. The authors of signed comments must refrain from providing qualitative evaluations of the work or recommendations for or against publication, as these will be ignored and editorially redacted. 
• No more than 1,500 words.
• Provided in a timely manner. In fairness to the authors whose work we are reviewing, we will not delay decision-making for signed comments if all our independent reviewers have returned their reports and the deadline for submission of signed comments has passed.
• Signed. We do not accept anonymous feedback by the authors whose work is being replicated or challenged in the manuscript we are reviewing. 

Signed comments are not peer reviews and, unlike peer reviews, they do not inform editorial decisions to reject a manuscript or invite a revision. The authors of signed comments have the strongest possible competing interest. Hence, their comments by definition cannot be impartial, and impartiality is the cornerstone of the peer review process. However, the authors of work that is replicated or challenged in a manuscript we are considering have an important role to play in the consideration process, as they have the most in-depth and detailed understanding of their work. Their engagement can lead to a stronger submission and a more constructive scientific process. 

Our editorial decisions are based exclusively on the feedback provided by our independent reviewers. However, the authors of signed comments may raise methodological issues that are not raised by any of our independent reviewers. If we judge these methodological issues to be potentially valid and significant, we will share signed comments with one or more of our independent reviewers, asking for their feedback. If our independent reviewers corroborate the validity of the methodological concerns, these concerns can then inform the editorial decision.

Although signed comments do not form the basis for editorial decisions, if we invite a revision, comments provided by the authors of the original work can inform our requests for revisions, and we ask that our authors provide point-by-point responses to these comments in the same manner as they respond to the feedback of our independent reviewers.

We implement transparent peer review for research manuscripts submitted after December 1, 2019. Although signed comments do not constitute peer reviews, they form part of the review record. The authors of signed comments need to be aware that, if the authors of the manuscript they are commenting on opt in to transparent peer review, their signed comments will be published along with the manuscript.