I get asked to review a large number of submissions to second- and third-rate journals.
For a long time now, I’ve had a policy of agreeing to review the paper if it looks like a junk paper that’s an easy reject. If I do so, I usually try to review the paper immediately, which (if the paper is really junk) takes about 15 minutes, maximum. (If a paper looks interesting to me, I may agree to review the paper but I won’t get to it right away and it will take me longer. If the paper does not look like garbage but does not look interesting to me, I will decline to review it. If the paper was submitted to a top-tier journal, I will usually agree to review it assuming I am not over-committed already.)
I should be clear what I mean by “junk/garbage/crap”. There are really several categories here. There are the papers that are unreadable due to poor exposition, awful English, formatting, etc. There are the papers that prove trivial (or known) results, and papers that prove uninteresting results. Then there are papers that have the potential to be interesting, but do not provide any formal definitions or proofs. (In the latter case, depending on the result, I may encourage the authors to resubmit with proofs.) I’m really not talking about bad papers here; I’m talking about junk. (It’s amazing to me that there’s so much junk being submitted…)
The question is: is spending even 15-20 minutes performing this “service” worthwhile? Or should I not care so much about the fact that a junky paper might get published in a junky journal? What do other people do?