I have published an original research paper in what was claimed by Beall's list to be a predatory journal. Considering the way they reviewed my paper, the corrections they gave me, and the many citations from typical research papers, I don't believe that it is predatory, especially since I don't think that the journal conforms with the criteria of Beall's list of predatory journals.
Nevertheless, I want to know what negative impact publishing in a predatory journal has on admissions chances.
Beall's List sometimes overshoots, though it's a good starting point.
I wouldn't say publication there will automatically hurt your admission chances, as especially if you're very junior I'd actually assume you had been naive. What it likely won't do is help all that much - predatory or not, it's doubtful it's a particularly well regarded journal in the field.
I'd also be careful how I presented it. In your cover letter, if you mention your work being published in "such notable publications as the International Journal of Obviously a Scam..." then it's likely I'll convert my impression of you from naive to oblivious. And while I've never seen this done with a predatory journal, I've definitely seen some people tout papers in pretty low-ranked journals as if they were at the top of the field, and that's always a bad sign.
It's not a death sentence, but you should be aware of what that paper is, and isn't. And I'd be prepared to talk about your experience, and how they did provide useful feedback, etc. Journals can be sincerely trying to get out of the predatory pool (or sliding into it...).
Despite the downvotes, I actually feel that this is a relevant question that should be answered. I have some experience with something similar - I've published in a journal that appeared on beall's list as well, unknowingly. After my own investigation I feel that the journal doesn't really fit the definition of "predatory" - it was open access/pay to publish, but I was rejected the first time and made a second contribution that was accepted. If I hadn't been rejected, I certainly would have been more concerned once I found out the journal was on Beall's list.
That being said, I feel that the answer to the question lies in two things:
a) What else have you done/published? If this is your only publication, then I'd be very careful trying to convince people that it is high quality.
b) How are you presenting it? For instance, I present the papers I had accepted by that journal as part of my list of publications, but I certainly don't overly emphasize them. In fact, I emphasize my top-tier journal articles far more, for obvious reasons.
Ultimately, I don't think that you're going to get rejected for having it on your resume, but if it's the only thing on your resume it certainly won't make your application stand out.
