Exploratory analysis of text duplication in peer-review reveals peer-review fraud and paper mills

Comments received from referees during peer-review were analysed to determine the rates of duplication and partial duplication. It is very unusual for 2 different referees to submit identical comments, so the rare cases where this happens are of interest. In some cases, it appears that paper-mills create fake referee accounts and use them to submit fake peer-review reports. These include comments that are copied and pasted across multiple reviews. Searching for duplication in referee comments is therefore an effective method to search for misconduct generally, since the forms of misconduct committed by paper-mills go beyond peer-review fraud. These search methods allow the automatic detection of misconduct candidates which may then be investigated carefully to confirm if misconduct has indeed taken place. There are innocent reasons why referees might share template reports, so these methods are not intended to automatically diagnose misconduct.