I think that it is a bad idea to keep search engines from spidering MO. One of the things which works well about the original stack overflow site is that people can often find answers to their questions by just googling for previous similar questions, and I thin the same could be true of us. For example, right now we are the second google hit for

"Godel's theorem" "excluded middle"

Hopefully, anyone who is having the same confusion as vonjd will now find a good explanation. Of course, I cheated: I already knew that MO contained a good answer to this question. But I hope that, as MO grows, it will contain more and more answers to common questions.

The software already has a solution to this: people with at least 3000 rep can vote to close questions. Perhaps we (as I'm one of them) should be more stringent in using this ability. And maybe the moderators should think about deleting posts that have been closed if the question is of "homework" type.

This solution is fairly robust because it will be the more able mathematicians who get enough rep to vote to close. The list is growing, and there's a substantial number of people who are fairly near to the 3000 borderline. At the moment, though, I'm a little hesitant on using these Advanced Powers - but if I knew that I was acting in accord with the wishes of the moderators, I'd be a bit more forthcoming in voting to close homework questions.

I'm always extremely excited to see that someone has voted to close a question -- it means that if I'm considering it I just go right ahead. Often I wish my "vote to close" didn't have instantaneous effect, so I could be more sure I'm following consensus.

More generally, I don't think we're experiencing any real downward trend in terms of the appearance of homework questions -- rather that we've just had a bad weekend. If anyone would like to compile some statistics that would be great.

@Harrison: You've just failed Stats 101. You shouldn't be counting the total number of such questions, but the proportion. Plus you should discard at least the period where Anton expressly forbade anyone to link to MathOverflow. Also, these are net number of downvotes, not gross. For example, my question on walking in the rain shows a positive count of 6 votes and 2 favourites; however I can see from my records that it also garnered 8 negative votes (whence it actually got 14 positive votes putting it 4th on my list!).

@Scott: I had an idea about the moderator-as-dictator problem. It may not be possible, but perhaps the moderators should each have two accounts: a "normal" one and a "moderator" one. They do most of their stuff with their normal account, including accruing reputation, and only use the moderator one for moderation stuff. Then, for example, Ben and Anton would be able to merely "vote to close" as they wish and it would also be clear that when you vote to close a question then you are acting slightly outside the community (I don't wish to imply anything wrong with you doing that, I think it's very important that you do so). Although there aren't many moderators, they do set the tone. But there is a problem with that: if they go around closing lots of questions then the rest of us think "It's the moderators' job to close questions" but if they go around not doing so then we think "They're not doing it, maybe I shouldn't be closing questions either.". If you can split your accounts, you can give us an example without being dictatorial.

@Alberto: Possibly part of the problem is that there aren't many people with at least 3000 rep. So you should go out and find people near that boundary and vote for their answers! Slightly more seriously, most of them are in the US (I think only myself and Ilya aren't) which means that there are significant periods when there's effectively no moderation. However, these things will change as people use the site more.

Whatever the merits of your solution, it won't happen. The makers of the SO system have no incentive to put that limitation on their software because over on the Mother Site, every question is a homework question! By that I mean that on stackoverflow, the point of asking a question is to get an answer not to understand the answer.

For me, that's the crucial difference between a "homework" question and a "non-homework" question. I would not vote down a question that said "I've been trying to solve this elementary problem. I've tried this, that, and the other but can't figure out what I'm doing wrong. Can anyone give me a hint as to the right way to approach this problem?". I would vote down a question that said "I want to solve this difficult problem but I'm too lazy, can someone else do it for me.".

As explicit examples, take this question. That, I think, is a fantastic question. It gives the context, it locates the exact piece that is confusing the questioner, and it asks for enlightenment rather than a dull answer. However, it is a homework question. Well, not quite literally - I happen to know that this person is reading this book independently - but the level is of an undergraduate differential topology course.

Now take this question (bizarrely, he's accepted his own answer to this question where he admits he was looking for a better one). To me, that reads as "I can't be bothered to do this tedious calculation, can someone do it for me?". The question is far too localised in that it is highly unlikely that anyone has done that specific type of problem before so anyone who can say something sensible is going to have to essentially solve the problem themselves. There's no indication of what he's tried (since he admits in his sketched answer that the method he knows is "tedious and unenlightening"), no context, and no indication as to what an appropriate level of answer would be. For me, this question is "homework", even though it's unlikely that an undergraduate would have a clue what was going on.

(I hope Theo doesn't mind me picking on him!)

As a final example, take this question. I hope Scott won't mind me pointing out his comment following his answer!

My point is that the classification as "homework" is fairly arbitrary and it is best to let the community decide and take appropriate action. I see no need for any new technical stuff, what is needed is more involvement from those with enough rep (myself as guilty as the next) but we need more guidance from the mods.

@Harrison Brown, thanks for the statistics. At some point we'll be able to produce a database dump, after which we'll produce all sorts of statistics!

Given that the trend on "bad questions" is only marginally positive, and I think everyone will agree the trend on "good questions" is clear, I'm happy to claim that my point is validated -- the bad questions aren't a problem at this point! :-)

@davidk01: No, someone is likely to answer it, and if we let that slide, the “riff-raff” (as Andrew calls them) will take over. (I actually don't think there is anything wrong about the so-called riff-raff, but this site wasn't built for them, and we can't let them take over.)

The point of my parenthetical remark was that “riffraff” (I looked it up, it shouldn't be hyphenated apparently) is perhaps an unnecessarily derogatory term, though it may be okay to use semiprivately here on meta. We do not wish to discourage anybody who is interested in mathematics from learning more about it – quite the contrary. But the site is made for mathematicians, and if it is to be usable to mathematicians there is a need to discourage (there is that word again) the asking of questions that aren't of interest to mathematicians, preferably in a nice and non-offputting way. Otherwise, the people we want to attract will have a hard time finding interesting questions, and they'll lose interest ang go away. Heck, I am already having a hard time myself, finding the occasional nugget in between all the algebraic geometry. 8-)

@davidk01 and @Harry. This is unacceptable, even here on meta. Stay on topic, and please try to ignore each other on meta in future. Nothing either of you has said to each other of late has been helpful to anyone else using meta, and it's downright boring.

I would be happy to furnish both of you with each other's email addresses, and you can continue this in private.

@davidk01. Sure! While I've written to many people via the addresses they've filled out at mathoverflow, I've never revealed this information (and I've been careful when writing to multiple people to BCC). Presume innocence and assume that I would have checked with both of you first via email. :-)

On a related note: I would strongly encourage you to use your full real name both here and at mathoverflow: (a) you have to use your real name on job applications, might as well get it out there earlier, (b) using real names tends to moderate language and behaviour!

In fact, I'm sort of tempted to propose a new policy: pseudonymous and anonymous users aren't allowed to get into fights on either MO or meta!

As the one who introduced the term "riff-raff" (check your sources, hanche! I know that you're in the US at the moment but there's no need to go native), perhaps I ought to explain it's use as I (a native speaker of English, perhaps the only one here?) use it. It certainly used to be derogatory, but now it's actual use is much more ironic. The user of "riff-raff" should be perfectly aware that he or she is "putting on airs" that are probably undeserved and phrases like "Let's keep out the riff-raff" should be seen as being so over-the-top that everyone else says "Yes, very funny, but who actually do we want to exclude?".

The perfect example of its use was in an episode of Fawlty Towers where Basil Fawlty puts in an advertisement for his hotel "No riff-raff", hoping to attract a higher class of client. The irony being that the Lord that actually came to stay at the hotel was a con man. (Of course, Basil Fawlty wasn't being ironic, but John Cleese and Connie Booth were in putting those words into the script.)