@David,

Any arguments against the stumper tag?

no arguments against, but I think it's better to go slowly and explicitly ask people for comments with first few retags.

@Anton: I want some finer way to find out if there's something still outstanding in a question. I think that the "hasaccepted:0" is too coarse for this as I think that on MO there'll be many more questions that just cannot have an accepted answer but still can be "resolved". The idea of writing a community wiki answer and then accepting that is good, but I suspect most people won't do that. If there was some way to get people to retag their questions after a week then that would be great. Rather than the "Have you considered accepting an answer or offering a bounty" message you could say "Is this question still unresolved? How desperate are you for an answer?".

Any arguments against the stumper tag? If not, I'll probably start using it, and do some retroactive tagging, this weekend.

On the other side, I have no particular interest in working on problems with a bounty or not. I'll think about a problem if it's interesting and if I think I can contribute. Knowing how much the other person needs the result would help me decide on how much effort to put in, but a bounty ain't gonna cut the mustard for me.

I've wanted to "accept" several answers to questions, or to say that this, that, and the other together make up the correct answer.

One possible solution would be to post yourself a community wiki answer, summarize other answers there and accept it. You can then make a note that others can add to it directly.

would it be a good idea to create a tag for questions that have resisted serious thought, but have not been found as open questions in the literature?

I'd like a way for the questioner to say "I'm still not happy with what I've gotten here"

The asker can post a bounty on the question. This mechanism signals to community that the question is a stumbler and that the asker cares about it (which is important since one possible reason why the question has no good answer could be because there was not enough work done to ask a well-defined question).

Usefully, there is a special tab for questions with bounty which seems to solve the problem of finding these questions + a special thrill one may feel when receiving a bounty should be a good motivator.

David, your idea about a tag seems to me to differ from the bounty mostly in the fact that the bounty question can last for at most a week and then one answer gets chosen automatically. One may see this as a bug, I see it as a feature -- if the question survives for a week without substantial progress, it's essentially an open problem; if there is some progress it probably makes sense to post a different question.

To summarize, I think the questions without an accepted answer should be an anomaly so participants should be encouraged to accept "this is the best we all could come up with" answers.

I find that the "a question has one answer" model just doesn't fit. I've wanted to "accept" several answers to questions, or to say that this, that, and the other together make up the correct answer.

So I'd like a way for the questioner to say "I'm still not happy with what I've gotten here" and for that to be what comes up as "unanswered". It'd also be useful if the questioner has to actually do something for this to apply, since if they aren't bothered enough about the question to keep coming back and saying "I'm still not satisfied" then I'm not bothered enough to try to answer it.

I think it is probably good that the unanswered button behaves the way it does. I think the intended use of the "unanswered" button is that someone clicks it and scans through to see whether they have anything obvious to add that others missed, and these questions won't meet that description. But it bothers me that these questions are being called answered when they are not.

So, two thoughts. First, can we rename "unanswered"? My first thought is "needs attention", but hopefully someone here can think of something better.

Second, would it be a good idea to create a tag for questions that have resisted serious thought, but have not been found as open questions in the literature? I'm thinking of "stumper", but maybe someone can do better. The trouble is that I can't think of a tag which is self explanatory, and there is no way to make a tag link to a FAQ.