There is no agreed upon list of criteria that a journal must meet in order to be called a "predatory publisher." It is a somewhat subjective term. Jeffrey Beall, creator of the Beall's list, describes predatory publishing as:
"Predatory open-access publishers are those that unprofessionally exploit the gold open-access model for their own profit. That is to say, they operate as scholarly vanity presses and publish articles in exchange for the author fee. They are characterized by various levels of deception and lack of transparency in their operations. For examples, some publishers may misrepresent their location, stating New York instead of Nigeria, or they may claim a stringent peer-review where none really exists."
However, Monica Berger and Jill Cirasella, both librarians at City University of New York, remind researchers that:
"Quality and reputation are independent of openness, that OA journals do not necessarily charge fees, and that fees do not necessarily imply predatoriness."
There are many high quality OA journals out there. It is a matter of doing your research to ensure you are publishing with the right one.
Quotation and Illustration (illus.by David Parkins) from https://www.nature.com/articles/d41586-019-03759-y
Contact the library with any questions regarding a journal. We will be happy to help you verify the quality of any OA journals!
