"Predatory journals and publishers are entities that prioritize self-interest at the expense of scholarship and are characterized by false or misleading information, deviation from best editorial and publication practices, a lack of transparency, and/or the use of aggressive and indiscriminate solicitation practices."
Grudniewicz, A., Moher, D., Cobey, K.D., Bryson, G.L., Cukier, S., Allen, K., ...& Ciro, J.B. (2019). Predatory journals: no definition, no defence. Science (576)7786. 210-212.
While the open access movement has given rise to predatory publishers, all open access journals are not predatory. Regardless of whether a journal is subscription based or asks for an APC, authors can critically evaluate journals by looking at certain characteristics, while keeping in mind the following:
Whether deciding to publish in a traditional or open access journal, it is important to carefully evaluate the credibility of the publisher and the journal.
Cabell's Directories includes a tool called 'Predatory Reports' that uses established criteria to identify deceptive, fraudulent, and/or predatory journals.
Some other lists that you may want to consult, however note that these lists may not be up to date or as systematic with their evaluative criteria.
While there is no single criterion that can indicate high or low quality, organizations such as COPE (Committee on Publication Ethics) and others publish guidelines for identifying predatory entities. The following list of characteristics are derived from the Principles of Transparency and Best Practice in Scholarly Publishing.
Some characteristics of predatory journals and publishers:
Some characteristics of quality journals and publishers:
Criteria for avoiding predatory conferences is similar to that for journals.
Use the criteria from Think, Check, Attend to evaluate conferences.
Read this 2016 Science article by Adam Rubin - Dubious conferences put the 'pose' into 'symposium' - to learn more about how predatory conferences work.