I do not understand why some people/moderators have such strict notions of "what is appropriate" for mathoverflow. It reminds me of the beaurocracy for beaurocracy's sake of Wikipedia. In my view the criteria for whether a question should be appropriate should simply be "is it likely to be of interest to people working in mathematics at the graduate level or above". Open-ended and vague questions about the "meaning" of something ARE of interest to graduate students and mathematicians, as they give a chance for people to give their diverse philosophies and intuitions about the quintessential meaning of a topic. I know that some people argue that "Mathoverflow" is just "not the right place" for things that would create discussion. Well, where else should such questions be asked? It is best to develop _one_ community of mathematicians sharing their knowledge on the web rather than a bunch of scattered ones. Mathoverflow seems to be doing well and we should make it a hub for all graduate students and mathematicians within reason.

An example of how this trigger-happiness has gone astray would be the question someone posted about getting errata for the Cassels & Frohlich book. The poster of that question was very concerned that his question was "not appropriate" and would get closed. How is asking for errata for this important book not an absolutely great question to ask this community? The fact that he/she was concerned is a sign to me that this trigger-happiness has had a detrimental effect on people's psyches.

@beren: Well, first things first: Kevin Buzzard is a he, not a he/she. I strongly suspect that his psyche is pretty much the same as it was before he asked the question, but I'll let him speak for himself.

@Qiaochu: With all respect due, it is hardly a "community consensus" when members of the community (such as myself) don't agree; although it does seem that my complaints don't completely align with the vision the creators of this site had in mind. And to be honest, I'd prefer to have one website that I visit regularly for engagement with other mathematicians outside of my department rather than one website here, another there, maybe a forum over here, etc. etc.

As an example: I see all these people complaining in meta about soft-questions on MO. Isn't a sensible solution to just find a way so that those people are not disturbed by these soft-questions rather than trying to discourage soft-questions. Surely the ranking can be changed to not count the super-high votes of questions labelled "soft-question" so strongly, so they won't flood the main page, or give people the possibility of telling the software not too show questions with that tag, and then... problem solved?

I must say though that I strongly feel that undergraduate homework questions don't belong here. It is a question of audience. There exist very good resources for undergraduates to go and ask questions at that level, but not many resources (unless you want to get into blogging and what not) for actual mathematicians to communicate with each other over the web. MO has great potential for helping us share our knowledge with each other, and I just feel that much of the bureaucratic talk I've seen on MO is quite silly really. Like missing the forest for the trees.

One major problem I have with the limited appropriateness is that frequently math questions on stackoverflow.com get referred to this site, since SO tends to have a fairly limited math background. However, those questions are usually not "mathy" enough for this site. So then programming-related math questions (typically more in the realm of applied math, or just generally easy math) have no home. I don't like this situation and would like MO to accept those questions, since it often takes a mathematician's point of view to give those questions a good answer.

I stand on beren's side on these issues, though I think it is a complicated issue and I'm not sure how strongly I stand on beren's side. I think that this beren makes great points and that we should definitely discuss this further. I think this is a great community, and it can probably serve as a great venue for certain things that don't necessarily strictly fall into the "math question" category. The feeling seems to be that if we allow that here, then it can quickly run amok and overtake the rest of the site, or at least become a significant distraction --- but is this really true?

Yes, I don't think this should become a kind of Anti-Jeopardy Game Show, where you have to pose your question in the form of its own answer.

@beren (and those that hold the same view): Part of one of my posts in another thread:

You can ask, "why close questions at all?" After all, it's not like we're trying to save space on a hard drive. It's not at first thought unreasonable to say, "let's just leave everything open and ignore what you don't like." One problem is that it's not so easy to ignore stuff (it sounds easy, but it amounts to doing the work of finding what you're interested in, which is quite hard). Another problem is that allowing questions you don't want draws the wrong people and the wrong attitude to the site. As Emerton said, "things that will appeal to one person, or scare them away, may have the opposite effect on a different person." Attempting to target both of those people with the same website is clearly a bad idea. Not everybody has to use MO, and MO users don't have to use it all the time. Having some people trying to play tennis in the same place as others are trying to watch TV is annoying for everybody.

I have to agree with Qiaochu that you don't really want to have a single site for all mathematical activity of any sort, because there are lots of different sorts of mathematical activity, and it's annoying to have them all going on in the same place. Benjamin says, "... and listen to them ramble about the subject for a while; this is often the most productive and interesting time I'll have in a day." This is an example of doing the right thing in the right setting. Vague discussions can be fantastic, but they require a lot of back-and-forth. They just cannot be made to fit in a Q&A format without seriously compromising them.

I'm open to discussion, but I really think we should reserve MO for focused questions that have answers. If thinking about such questions is (metaphorically) watching TV, then MO is the living room where people come to watch TV. If you'd like to play tennis, that's fine, but please do it elsewhere.

@Victor Liu: Programming is far from the opposite of mathematics, and I expect that many if not most of the SO regulars are more than qualified to handle the "easy math" questions that sometimes get forwarded to us. It seems more likely to me that they don't find such questions very interesting but are trying to be polite by at least suggesting somewhere else for the questioners to go, even if their suggestion is not the best thought-out.

There are plenty of other sites which welcome questions in mathematics (at least) through the undergraduate level, including Dr. Math, NRICH, ask an algebraist/topologist/analyst and sci.math. I don't see why MO is obligated to take on this responsibility.

So you know, I have generally spoken out in favor of the "inclusionist stance" on MO: if a question is of interest to _some_ professional mathematicians -- even if it also or even primarily involves physics, computer science, history, philosophy, etc. -- and seems to admit at least one correct answer, I think we should welcome it.

The main purpose of this site is indeed for professional mathematicians -- i.e., people who spend the majority of their work time learning and researching mathematics -- to help each other out. This is a very worthy goal and is hardly one which is lacking in ambition: the fact that some student somewhere who has no one to talk to directly can ask a question which some of the top experts in the field will take a crack at within minutes or hours is really a wonderful thing. It's also a public showcase for our profession, i.e., we help each other out, as a matter of course, with no specific recompense except possibly for the gradual increase of one's reputation within the community.

This site is unusually integrated: undergraduates and Fields Medalists can and do ask questions back and forth, and each can learn from the other. This necessitates that younger people (especially) adhere to the very high standards of professionalism and courtesy which permeate the "adult" academic world, lest they acquire a negative reputation from their interactions on this site. (Here and above I am using "reputation" in the conventional sense, which is very roughly approximated by the site's system of reputation points.) I visited your user page and found some language on it that is unprofessional and discourteous. I submit to you that this is not really the impression you wish to make.

@Victor: I do see your point regarding mathy questions coming from SO, but it's not all bad; for example, http://mathoverflow.net/questions/11444/good-algorithm-for-finding-the-diameter-of-a-sparse-graph is a great question and the votes and answers reflect that. One issue with questions coming from SO is that they are often phrased very vaguely - not in the sense that someone doesn't understand a concept thoroughly, but in the sense that they leave a lot of terms undefined, which annoys mathematicians a great deal (it had to be said). http://mathoverflow.net/questions/9606/thousands-of-rays-intersections-with-triangles-in-3d-space-closed is an example of such a question; see the comments. Another poorly-phrased question is http://mathoverflow.net/questions/550/identify-the-function-closed. The clarity of a question matters much more to me than whether it is "sophisticated enough" for MO and it just happens that many questions from SO are unclear.

An issue which maybe should be discussed in a separate thread is that I don't think most newcomers realize that their questions can be reopened if they edit them properly.

Thanks for people's responses. Just for the record, it's not that I'm against closing questions; like many of you, I completely agree that we need to be careful lest MO become saturated with an "undesired" crowd asking basic mathematical questions (which, as has been noted, can be asked in many other more appropriate places). It's just that I agree with Benjamin Weiss that surely the most important criteria for a question should be "to be of interest to math graduate students and research mathematicians". Of course, it is not my site, etc. etc., but I think that the site will suffer when people are too scared to ask questions because of some excessively strict notion of what an appropriate question is, and in lurking and reading the discussions I've seen the beginnings of a strong bureaucracy developing. The danger is that it might become like Wikipedia where people are more concerned with whether a question "conforms to the policies" rather than whether it would be useful for the "appropriate" users of the site. And I think that people's worries that problems will be caused by "vague questions devolving into discussions (which doesn't work with the QA format of the software)" to be very unconvincing unless such problems _have_ actually occurred. Hope everyone has a great day.

I sort of want to say "I agree with all of you!" But that would sound silly.

I don't think there is -- and I don't think there should be -- any sort of bright-line test for what's appropriate as a question and what isn't. Five or six years ago, I edited Wikipedia, not as a hardcore user, but I probably amassed a couple hundred edits. Eventually I moved on to some other interest, and stopped editing. Now that I am less stupid, I occasionally go back and make new edits. But if it's about something that anyone cares about, and it's more substantial than correcting a typo, odds are that it'll launch a heated exchange on the discussion page with people throwing about obscure "guidelines" or "essays" like WP:XYZZY and WP:FHTAGN.

The thing about MO is there's not a cabal of moderators whose word comes down from On High no matter what the unwashed masses decide. In a sense, I guess, we're organized in a "leftist" manner, as opposed to the Jimbo Wales, Registered Libertarian-led Wikipedia. And -- considering my personal politics are probably to the right of, oh, 75 to 80% of MO users, bare minimum, this next part is going to be hard for me to type -- that may be a Good Thing, that this site is run very much "from the bottom up." It means, to start with, that you -- yes, you! -- can help shape policy. I've done so in the past, sort of; I proposed the "big-list" tag that functions to some extent as a pressure valve in the soft question wars. It means that if you ask good questions and post good answers you can vote to close or open questions. If you ask really good questions, and stay at it long enough, you can even get shiny moderation tools. Of course this could all fall apart completely, but I don't see it happening soon. So, beren, it is your site, and we're happy to have you. (As long as you're not trolling or asking freshman calculus questions.) And I think the fact that it's your site, and Noah's site, and Harry's site, and my site, and Greg Kuperberg's site, is what's leading to the heated discussions about "appropriateness," not some slavish dedication to a prescribed ruleset.

Random thoughts:

Plus, if you don't like it, you can always leave. You can even come back later! Or just cut down on your visits! I've been a lot less active over the past couple of weeks -- not because of any sort of falling-out with MO, but because I've been investing a lot of the MO energy into Tim Gowers' new Polymath project. When that finishes (or gets to a point where I can no longer follow what's going on), I expect I'll post more again here, and I don't expect that it'll be a huge deal for anyone -- combinatorics questions might get answered slightly faster, and the average awesomeness level of the questions being posted will inch up. No biggie.

I don't think I've ever hesitated to post a question, except for one about tricks, and that wasn't out of worry that it would be downvoted (which it was, and then it was upvoted some too) so much as it was about worrying whether it would be redundant because of the (much under-used) Tricki.

I love meta for the frank but (mostly) professional exchange of views about MO's workings. Even when it's marginally on-topic. I don't love meta for the fact that half the threads seem like they might spontaneously degenerate into a shouting match. I think we all understand that the question of "where do applied math type questions fit into the MO paradigm" is a contentious one; if it really needs discussion that desperately, take it to its own thread?

"Even if there weren't anybody trying to watch TV in the living room, it'd still be an awful place to play tennis." This is a fantastic metaphor, even out of context. Anton, mind if I borrow it?

@Harrison Brown: You make some interesting statements about who MO "belongs to". But I haven't seen anything explicit from the moderators about this. I'd like to hear the moderators's thoughts on this. What kind of "government" do you guys envision for the site? (If any such thing has been envisioned at all.) How much "power" do you want to give to the "people" on the direction of the site?

MO belongs to the prime \mathfrak{p}, and I aim to keep it that way. Anyway, if you've noticed, many of the questions being closed are now being closed by non-moderators. It might be helpful if a vote to close is accompanied by a note why you think a question is salvageable or not. There's no point in getting someone's hopes up on a question that's just garbage. Something like "I voted to close this question because it was too vague. It has some potential, and if you're willing to work on it a little more, we can reopen it." or in the other case, "This question is not appropriate for MO because it's ... [too elementary, a homework question, too discussion-y, etc]."

@Gretar: unfortunately, the reasons for closure come from a fixed list specified by the software; as far as I know, there's no way for MO to change these.

I usually try to leave a comment when I vote to close a question, or vote for someone else's comment. Usually, it's just "This would be more appropriate on one of the sites mentioned in the FAQ.".

As for the "who owns MO". I think that the "MO is owned by the community" statement is a bit disingenuous. It is owned by Anton (and maybe the other moderators). The moderators run it, but they delegate some of their duties to other users. The way that they choose to do that is via the reputation system. So it's not really owned or even run by the community. But that quite nicely mirrors mathematics as a whole: to be a mathematician, you have to be accepted as such by other mathematicians.

Ultimately, if Anton decides that he doesn't like the direction that MO is going in, he can just pull the plug.

It's worth remembering when talking about "government" that Anton has his hand on the off-switch. :-) In principle at least, he could threaten to take his toys and go home, in order to get his way. Now of course this isn't going to happen --- at worst Anton would lose interest in mathoverflow and ask someone else to take over the top-level administrative duties, namely passing money from our generous funder (thanks Ravi!) to FogCreek and our domain registrar.

I agree: Aren't conspiracy theories and hypotheticals about "evil" moderators pretty bizarre things to spend time thinking about? :)

Toss in policy-judgement and you have the three branches of U.S. government.

Ha! Power is measured in watts! You've been caught! ;)

@Harry and @Beren, if it was my comment that you're interpreting as about "Anton as evil dictator", please don't! He's a good friend, and I'm almost entirely in agreement with him about how MO should work. I was just trying to point out that "MO is owned by the community" is only meaningful at some levels.

No need for evil dictators... Anton can become the Benevolent Dictator for Life as did Guido of python fame :P