There is not a standard definition of predatory journals. However, at their root they are designed to take advantage of the open access publishing model, which often requires authors to pay article processing charges in order to have their works published open access. They often quickly accept articles without any peer review or quality control, collect the article processing charge, and then post the journal article to their website. There is a range of minor to severe behaviors that can qualify a journal as being predatory. As such, determining if a journal is predatory or not is a process and can involve a number of subjective considerations. There are a number of tools and lists of characteristics that can assist in determining if a journal is predatory or not.