Predatory journals charge publication fees while failing to provide the editorial and peer-review services they advertise. For authors, the cost is not only the fee: work published there may be hard to find, poorly preserved and treated with suspicion.
A consensus definition
In 2019 Grudniewicz and colleagues reported in Nature a definition agreed by an international group of researchers, publishers and librarians. In summary, predatory journals put their own interests ahead of scholarship and are marked by false or misleading information, departures from good editorial and publication practice, a lack of transparency, and aggressive, indiscriminate solicitation.
Warning signs in practice
An earlier comparison by Shamseer and colleagues in BMC Medicine found that potentially predatory biomedical journals differed from legitimate ones in ways authors can check: spelling errors, distorted or unauthorised images, unclear editorial boards, missing retraction policies and unusually low publication fees.
The Editorial and Publications Division advises institute authors to check a journal against these signs, and to confirm its indexing and membership claims directly with the indexing body.