What does it mean to post a paper to arXiv? More specifically, a paper that has not been accepted to a peer-reviewed venue; less specifically, to any easily-searchable, time-stamped, respected depository.
Scenario A: You have a result, but there is no decent deadline for another few months. Maybe you know that a ‘competing’ team is working on the same result. Should you post to arXiv? Would that actually protect you from being scooped if someone else published the result in the meantime (perhaps at a venue that you deemed unsuitable)?
Scenario B: You are building on result B that has appeared in arXiv, but has not been accepted (yet?) at a peer-reviewed venue. You have verified the work in B. Can you reference an un-traditionally-published work?
Scenario C: You are reviewing a paper C and, being a diligent reviewer, you brush up on the latest in the area. You find a very relevant paper posted on arXiv, paper X, dated before paper C would have been submitted. Paper C makes no reference to paper X. What do you do if: Paper C seems awfully similar (similar techniques, similar results) to paper X? Does your opinion change if Paper C is a subset or superset of paper X?
I suppose as a reviewer, you would review the paper and point out paper X to the editor/PC member. But as an editor/PC member, what do you do? After all, it is possible for independent researchers to come up with the same result using similar techniques at the same time (I have seen this happen).
What does arXiving mean? Does it do more than provide an easy repository for papers? Do we (in TCS) treat arXiv differently than other areas?
A: I usually (but not always) wait until a paper has undergone at least one round of peer review (positive or negative) before arXiving. That means waiting until the conference deadline and then waiting some more until the conference notifications. If you’re in danger of being scooped, you’re being too trendy or too unoriginal. On the other hand, I think putting a draft paper (with full details!) on arXiv does provide a good claim of priority in case you are scooped; it’s just that it’s not a possibility I worry about very much.
B: Of course. It’s publically available; you can and should reference it. On the other hand, if you *haven’t* verified it yourself, and you’re not sure whether to trust the result, it’s probably better to ignore it than to badmouth it.
C: It’s a problematic case, but I don’t think my reaction would be very different whether paper X is on arXiv or already published for real.
It may depend on the field. ArXiving a paper means a lot to most researchers, since they are staking their reputations on it. The CS conference system is not exactly a peer review system, so if you are uncritically referencing conference-approved papers then you are making a *very* serious mistake.
Scenario A has happened to me. I think the arXiv provides some protection. This isn’t something I worry about.
Scenario B: I don’t see how you can *not* reference the work if you are building on it. Isn’t this Science 101?
Scenario C: Insufficient consideration of previous work is a good reason to reject a paper. If you want to be generous to the authors, then you might look into it further to get the explanation. But that is really the author’s job, not yours.