I have seen a journal, in the Computer Science field, that is predatory according to the Beall list (sorry if its not well written), but I see that this journal appears indexed in Scopus and Scimago; so I was wondering how to determine if a journal is predatory or not?
For example, I know that even some journals from Elsevier or Springer charge different prices for publishing an accepted article, and according to some colleagues if a journal charges for publication then it could be a predatory one, but the aforementioned editorials charge also so to whom believe?
I was also wondering if the B list is also accurate, I am starting to have my doubts about it.