Corrections, Expressions of Concern, and Retractions

PLOS publishes three types of post-publication notice:

• Corrections
• Expressions of Concern (EOCs)
• Retraction notices

As discussed below, we use these notices to address:

• Errors that impact an article’s interpretation or indexing
• Concerns about compliance with journal standards and policies
• Concerns that have implications for the integrity, reliability, and/or validity of published PLOS articles

In addressing issues raised about PLOS publications, we uphold our journals’ policies, publication criteria, and editorial standards, and we follow ICMJE and COPE guidelines, where applicable. The PLOS Publication Ethics team works in collaboration with journal editors on post-publication cases that involve serious ethics or integrity concerns, including those for which the issues may warrant an Expression of Concern or retraction.

Corrections

We publish corrections to address errors in PLOS articles if, per our editorial assessment, all of the following criteria have been met:

• The errors impact the main contents or understanding of the article. 
• The article's overall results and conclusions are upheld.
• There are no concerns about the integrity or reliability of the reported work.

PLOS may also publish a correction to address an error that affects key aspects of the publication’s metadata (e.g., misspelling of an author's name, or errors in the competing interests, funding, or data availability statement).

In most cases, a correction notice will appear as a post-publication notice linked to the original PLOS article. In rare cases, PLOS may choose to republish a corrected version of an article, replacing the original online version. When we republish an article, we generally publish an accompanying correction notice that is linked to the article and documents the changes.

PLOS does not publish corrections for typographical errors or other minor issues that do not substantively impact the article’s scientific integrity, understanding, or indexing. For these issues, authors are encouraged to update readers by posting comments on their article’s webpage. See the Comments guidelines for more information. Please email the journal office if you have questions about whether a correction or comment should be used to address an error in a PLOS article.

Expressions of Concern

Expressions of Concern (EOCs) are notices published at editors’ discretion to alert readers of serious concerns about published work. In most cases, we will complete the case’s follow-up before publishing a notice, but in some instances we may publish an EOC as an interim notice while PLOS or another entity is investigating an issue. An EOC may also be used as a resolution to a post-publication case if we reach the conclusion of our follow-up process and issues remain unresolved.

EOCs are written by PLOS staff and/or the journal’s Editor(s)-in-Chief or Executive Editor. When published, an EOC is posted at the top of the article’s PLOS webpage and linked to the article’s publication record, similar to a correction. An EOC not change the publication status of the linked research article. After an EOC is published, the same article may be corrected or retracted, or the EOC itself may be corrected or retracted, depending on the editors’ assessment of information, data, and/or materials received in subsequent discussions.

PLOS attempts to notify the authors of the affected article before publishing an EOC, but we do not require the authors’ approval or agreement. The editor may seek to publish data or other materials received from the authors as supporting files with an EOC; in such cases, authors are consulted and can elect not to have their files/materials published.

Retractions

As is discussed in COPE’s Retraction Guidelines, retraction is a mechanism for correcting the literature and notifying readers of major concerns about the integrity, validity, or reliability of an article. PLOS will retract an article if the editors determine that issues that are not resolved in our discussions with the authors warrant retraction per COPE guidance. PLOS may also retract an article if we determine post-publication that an article does not adhere to key aspects of the journal’s requirements or editorial policies; or if there are image or data concerns for which the original raw data are not provided, not available, or not sufficient (per our editorial assessment) to address the issues.

We may retract an article whether the issues have arisen due to honest error(s) or misconduct. In accordance with COPE guidance, PLOS does not adjudicate on intent or individual-level responsibility for issues raised, and we do not issue partial retractions.

When retracting an article, PLOS publishes a notice of retraction that explains the reason(s) for the retraction. The notice is posted at the top of the affected article’s PLOS webpage and is linked to the article’s publication record. An article can be retracted by its authors or by the journal’s editors. In either case, PLOS editors have final say on the retraction notice contents, but for author-led retractions the editors collaborate with the authors in preparing the notice.

We attempt to notify all authors of a retraction decision and the notice text before completing a retraction. PLOS may also notify other affected third parties of a retraction; this could include, for example, the authors’ institution(s) or another journal/publisher that has an article or submission involved in the case.

After an article is retracted, it is no longer considered to be part of the standing published record. However, as per COPE guidance retracted PLOS articles remain online and available*, with the retracted status clearly indicated. At the time of retraction we update the downloadable PDF that is available at the article’s PLOS webpage, so that for subsequent downloads the retracted status is clearly noted on the PDF.

_{*An exception may be made in rare cases where the availability of the article is deemed to present a substantial risk.}