tea.mathoverflow.net - Discussion Feed (Appropriate place to ask these types of questions?)

Ben Webster comments on "Appropriate place to ask these types of questions?" (1303)

Ben Webster — Thu, 31 Dec 2009 10:09:03 -0800

Right, I don't think that you're interpreting the phrase "too localized" in a way that will lead you to the right questions on the site. Obviously if you're asking a question abotu a book, it's good to provide enough context that people don't need to look at the book to know what you're talking about, but otherwise it's a great question. If someone mentions in a question that they're reading a book, and came to ask a question when they got stuck (as opposed to people who ask questions instead of reading the book), I say "Ah, here's someone who knows how to use MO."

Ilya Nikokoshev comments on "Appropriate place to ask these types of questions?" (1293)

Ilya Nikokoshev — Wed, 30 Dec 2009 02:06:51 -0800

I think Harry makes a very good point, the phrasing of questions about specific proposition can be too localized:

How to prove Proposition X in Y without Lemma Z?

Instead, they should be written to be self-contained (as Harry did):

How to prove that F is true without H? (I'm asking because I'm reading Y and it has proposition X and the proof seems to rely on lemma K which doesn't require H)

Harry Gindi comments on "Appropriate place to ask these types of questions?" (1290)

Harry Gindi — Tue, 29 Dec 2009 20:27:00 -0800

I guess, but it seemed too localized because it was about a proposition in a book, not because it was a specific question about a subject.

Ben Webster comments on "Appropriate place to ask these types of questions?" (1289)

Ben Webster — Tue, 29 Dec 2009 20:08:44 -0800

I think this is not a good way to interpret "too localized." It's taken for granted that things of interest to mathematicians may not be of interest to a very large number of mathematicians. But that's still a fine use of the site.

David Zureick-Brown comments on "Appropriate place to ask these types of questions?" (1261)

David Zureick-Brown — Mon, 28 Dec 2009 23:48:28 -0800

I agree that these type of questions are appropriate for MO.

Harry Gindi comments on "Appropriate place to ask these types of questions?" (1260)

Harry Gindi — Mon, 28 Dec 2009 22:23:23 -0800

Thank you for your help!

Anton Geraschenko comments on "Appropriate place to ask these types of questions?" (1257)

Anton Geraschenko — Mon, 28 Dec 2009 21:20:44 -0800

Looks like it worked. Also, it looks like MO just passed its 10,000-th post (that question was post number 10,002).

Anton Geraschenko comments on "Appropriate place to ask these types of questions?" (1255)

Anton Geraschenko — Mon, 28 Dec 2009 19:47:59 -0800

I don't know the material, but from the sound of it, I think you can make this into a fine question for MO. Just make sure to provide some background. But rather than asking, "where does the proof use X?" I would ask, "Is the result true without X?":

Is every left fibration of simplicial sets a trivial Kan fibration?

I'm reading Lurie's Higher Topos Theory. Lemma 2.1.3.4 says blah blah blah, but I don't see where the proof uses this and that hypothesis. Can it be removed to strengthen the result?

You may also want to include something about (counter)examples you attempted to construct. If you also explain whether you think the result should be true without the hypothesis (something like "based on the intuition that contractibility gives you X, and a trivial Kan fibration is Y, it seems like you really need contractibility"), then I think it would be a great MO question.

In fact, I might even try to make the question more localized by turning your "I don't see why we need S_t to be contractible to extend f' as stated in the proof" into a question. (maybe that would be less localized; it doesn't really matter)

Harry Gindi comments on "Appropriate place to ask these types of questions?" (1254)

Harry Gindi — Mon, 28 Dec 2009 19:18:28 -0800

I'm reading through Lurie's HTT, and every once in a while I have a question that seems like it might be inappropriate for MO (too localized) but is at too high a level to ask at the recommended places.

For example (quote from a question that I decided not to ask at MO):
"In the statement of Lemma 2.1.3.4 in HTT, where does the contractibility of the fibers come up in the proof? I see one place where contractibility is mentioned, but I don't see why we need S_t to be contractible to extend f' as stated in the proof.

The relevant page: http://books.google.com/books?id=CTe68E8wK4QC&lpg=PP1&ots=o8qXwh__pq&dq=higher%20topos%20theory&pg=PA67#v=onepage&q=&f=false "

It seems like this is too localized for MO, but I don't know where to ask such a question. Does anyone have any suggestions?

By the way, if any of you can answer the quoted question, I would appreciate it very much.