update: since we now have moderators, should we close this thread, using separate threads for each discussion, or should we keep it, appropriately reworded ?

Update II: This question is now closed, since there are sufficiently many 500+rep users, and posts can also be flagged if needed.

I am opening this thread to capture questions that should be closed.

Only users with rep over 500 can close a question, which currently amounts to five users. This question should help draw attention to those questions for the top users. Will be necessary until more users have sufficient rep and/or moderators exist.

Edit: One thing that we did with this thread on stats.stackexchange.com, was to vote down resolved answers so that unresolved ones would bubble to the top and get more attention. I suggest that we start doing that here as well.


closed as off topic by Suresh Venkat Sep 4 '10 at 20:43

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Well, this is sure awkward. – Daniel Apon Aug 24 '10 at 2:40
btw I've been voting to close questions since well before I've had 500 rep. There's also the option of using downvotes, which I've been using more recently - a -1 on a question is a good deterrent. – Suresh Venkat Aug 26 '10 at 4:32
@Suresh: It was possible to vote-to-close during private beta, but it isn't possible in public beta before 500 rep. – Jukka Suomela Aug 26 '10 at 7:26
Am finally at 1000 rep on the main site. will start editing if I can. I also deleted answers here relating to questions that I asked about which are now closed. – Suresh Venkat Aug 26 '10 at 21:47
Let's close this. We have moderators and we have plenty of people who can vote to close. – Jukka Suomela Sep 4 '10 at 16:32

13 Answers 13


I think that this is offtopic, but should certainly be closed until it is made community wiki.

Maybe someone who understands metaheuristics could post a sample question that actually has theoretical content? – András Salamon Aug 24 '10 at 11:53


Reason: Not a real question.

also note that this question has already received 3 downvotes. Long-term, that might be a better mechanism because just from the front page it's possible to tell that a question isn't worthwhile. – Suresh Venkat Aug 28 '10 at 7:25
It seems that the front page doesn't show the question any more. I guess questions with sufficiently many downvotes aren't considered "top questions", which makes sense. Hence even if you add a question here or vote-to-close, it might be a good idea to give some downvotes, too, to keep the front page clean. – Jukka Suomela Aug 28 '10 at 11:19
Once a question has sufficiently many downvotes (this one is now at -5) is that in and of itself a reason to close (or delete, once we have moderators) the question? I've noticed this particular question re-appear on the front page (I think) on and off, despite now having 5 downvotes. I think it appears whenever it or an answer on it gets edited. – Joshua Grochow Aug 28 '10 at 20:23
If I remember correctly, when enough people flag a question as spam it disappears from the front page. – Kaveh Aug 29 '10 at 3:44
This question, after 25 edits so far, is now shaping up to be a real question. Perhaps time to review some of the downvotes? – András Salamon Sep 1 '10 at 17:59

What are the most effective algorithms to find random number?

Several reasons to close apply. I think a question that asks for recent pseudo-random generators that are not covered by Knuth's TAoCP would be on-topic.

A degree of imprecision in a question is not always a reason to close. – Charles Stewart Aug 27 '10 at 19:22
There is a difference between "a degree of imprecision" and "requires significant interpretation to assign any meaning at all". Several nice answers provided are to the generic question of how to define random numbers (for which Wikipedia already has good answers, I think) and how to generate these. I'm not sure these bear much relation to the question as asked, which specifically ask about random number generation "without there being any relation from one set of random numbers to any other set". This is a potentially interesting question, but needs clarification as it stands. – András Salamon Aug 27 '10 at 22:03


What is the question? The paper mentioned in the original post seems to give a good answer.

If this isn't going to be closed, can't we make it at least CW? Suresh has >1k rep, is this enough to CW questions?

>1k rep is apparently not enough to CW questions :(. – Joshua Grochow Aug 28 '10 at 18:34
nope. not enough. We really need some moderators :) – Suresh Venkat Aug 29 '10 at 3:23

Which algorithms have the greatest impact on our civilization?; the answers might be interesting, but this is highly argumentative.

Resolved: closed.



Doesn't seem to make much sense.

let's let it develop a bit. again, without moderator powers, there's little we can do – Suresh Venkat Aug 29 '10 at 3:25

Learning quantum CS

Reason: voting to close as exact duplicate (OP concurs) of http://cstheory.stackexchange.com/questions/482/what-is-the-quantum-computational-model

There's a difference in the kind of answer sought: one wants summary explanations, the other wants a course of study. I'd want the scope of the former broadened before voting to close. – Charles Stewart Sep 1 '10 at 9:56

Question on "Why is P v NP so hard?" is subjective and would lead to a discussion.

Resolved: Closed.


Is there a complexity theory analogue of Rice's theorem in computability theory?

Close reason: 1) too vague; 2) under a reasonable interpretation, it is essentially a duplicate of Can it be determined if language L lies in NP?. It's only sort-of a duplicate, but I believe the answers to the two questions are identical.

Resolved? Despite the fact that the questioner has since clarified that he was essentially looking for a proof that $P \neq NP$, Ryan Williams's answer is interesting enough that I no longer think the question should be closed. If you have a different opinion say so in the comments.

To me it seems a reasonable question to ask. The fact that it is related to another question surely only means that any answer could point to the other question and point out the similarities. Perhaps simply asking the original poster to clarify the question is a better solution than closing it? It seems to me, at least, that we are being maybe a little too aggressive with closing some of the questions. – Joe Fitzsimons Aug 27 '10 at 3:08
I think this question could be developed further. – Suresh Venkat Aug 27 '10 at 4:45
Yes, this is way too aggressive. I am not sure you are fairly reading the question. – Ryan Williams Aug 27 '10 at 5:42
I wasn't sure about the question, but Ryan's answer indicates that it has merit. – Suresh Venkat Aug 27 '10 at 6:42
Perhaps I was a bit too aggressive. Ryan's answer to the question is very interesting. But if you check turkistany's recent comments, he was indeed looking for a property of a language that could be proved to use it is not in P, that is, a proof that $P \neq NP$. – Joshua Grochow Aug 27 '10 at 15:07
I don't like singling people out, but turkistany's questions are models of confusion. There's often an interesting nugget lurking inside, but it takes a lot of editing to bring it out. To whit, cstheory.stackexchange.com/questions/674/… – Suresh Venkat Aug 27 '10 at 16:21
I agree with Suresh. There is something else which does not seem nice to me: posting a bunch of questions one after another in a very short time. I consider this as a possible sign that the author is not really interested in the questions. (He has posted 6 questions in a relatively short time.) – Kaveh Aug 27 '10 at 18:28
@Kaveh: in and of itself, posting a bunch of questions in a short amount of time is not a bad sign, particularly when one first joins the site. Some people just have lists of boiling questions that they were waiting for an outlet for, and this site is it! But I agree that continuing to do that over time, particularly when the questions are poorly worded and confusing, is probably not a good sign. – Joshua Grochow Aug 27 '10 at 19:46
I would prefer that someone who posts 6 one-liners in short succession take the time to turn a few of these throwaway queries into slightly more carefully worded questions. I am sure Suresh has better things to do than providing copy-editing services to someone who could have used online tools like wordnik.com or en.wiktionary.org to check usage and spelling. – András Salamon Aug 27 '10 at 22:14
hear hear. I'm only editing because I don't want the site cluttered with junk. Unfortunately, this has the side effect of bumping the question back to the front. – Suresh Venkat Aug 29 '10 at 3:27

Best 2D Cutting Stock Problem Algorithm.

Close reason: Not a real question.

Resolved: Closed by community.



As pointed out by a commenter, this question is appropriate for StackOverflow, but not TheoryOverflow (or whatever we're calling this site nowadays).

Resolved: Closed by community.


What is known about NP-hard set properties?

It's not clear to me what the question even is.

Resolved: Closed by community.

@Suresh: I added a comment on the original question with a reasonable interpretation of what turkistany might mean, and if that's indeed what he meant, it's not such a bad big-list/CW question. I say let it develop / wait and see what turkistany's response is. – Joshua Grochow Aug 29 '10 at 21:31
not sure his response (just in) clarifies anything – Suresh Venkat Aug 29 '10 at 21:53
I thought his response clearly implicitly accepted my interpretation, and just pointed out that he wasn't only looking for conditional properties (though I doubt many unconditional properties, if any, are known). – Joshua Grochow Aug 29 '10 at 22:59
@Joshua: You have been extremely kind and patient with your attempts of saving this question, but I'm not sure if it is a good approach in the long run. First, it sends the message that people are interested in this kind of unclear questions and they are happy to help. Second, if you manage to turn an unclear question into a gem, then people start to upvote it and the original poster gets rewarded. I would rather see this kind of questions closed; if someone can extract some interesting ideas, they can open a new properly formulated question (giving credit to the closed one). – Jukka Suomela Aug 29 '10 at 23:35
@Jukka: Thanks. I agree with your suggestion, particularly with regards to discouraging unclear questions. Too late for this one, though, since I already edited it to a reasonable question. If there is ever going to be something like a "Moderators FAQ", your suggestion should be added to it. – Joshua Grochow Aug 30 '10 at 0:45
My thanks to Josh also. I feel, though, that we shouldn't rush to close these questions. I realize that reformulating vague questions to make some sense requires time out of the moderators, but I think/hope as the number of moderators grows, this will become less of a problem. – arnab Aug 30 '10 at 4:15
I think his questions should not be edited, let him edit them himself, and if he can't make them reasonable, let them get closed. If you see some interesting way to make the question reasonable and think it is interesting ask it as a new question. My opinion is that he is not really interested in the questions he is asking. He should be asked for the motivation behind his questions and what he has done himself before asking them. – Kaveh Aug 30 '10 at 6:05
Good comments, everyone. It doesn't make sense for someone else to get reputation b/c another person decided to be generous and make their question readable. – Ryan Williams Sep 4 '10 at 17:42

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