# Full question statements in the title

Look at the following question:

Let $A$ be bounded below, and $B = \{b \in R : b$ is a lower bound for $A\}$. Show that $\sup B = \inf A$.

I edited it to "Supremum of lower bounds equals to infimum". Am I doing something wrong? My intention was to make it easier for the further searches of the question.

• The more important point is for the body of the question to be self contained - it should not be necessary to read the title to know what is being asked. In this case, I prefer your shorter title over the long one; something like "Show the infimum of a set is the supremum of its lower bounds" has the same information in plain English. It should not be necessary to mention $A$ or $B$ explicitly in the title. – Carl Mummert Jan 16 '17 at 15:36
• I personally like the way Arturo once put it: "The title is an indexing feature, much like writing the title of a book on the spine to make finding the book on the bookshelf easier. But you don't expect the book to start at the spine." – J. M. is a poor mathematician Jan 16 '17 at 17:08
• Your title is much better! Because it is easier to google! The original statement has this defects: It has $A$ and $B$ sets, which the person who googles it could be using other letters, and also the question could be googled without making reference to the set $B$, which you got rid in your title. In the old title there are words such as "define" "below" "be" "Let" "show" which are not describing the problem, in your new title, the utility/specificity gained per word is much greater. – Santropedro Jan 19 '17 at 22:36

I think your title is better as a title. But, we want users to write informative titles and 'the question again' is in a way the best we can realistically aim for. The alternative would likely be to have "Question on supremum 13" not what you wrote. If I recall correctly, there is even a recommendation somewhere "Make your question your title." This then is taken in a literal way by some (to the extent of not repeating the question in the body, though I believe the recommendation to do this was added at some point).

That said, to have the full question in the title can actually be helpful in certain cases, in particular when searching for something, as the list of results will contain the title in full.

Some might also argue that the formula is easier to parse, than your phrase, but that is a matter of taste.

To sum it up, I would not say you do something wrong, but in the interest of global utility you might focus on improving terribly uninformative titles into something meaningful rather than on making arguably too verbose titles more title-like.

• Another thing to think about is that the title may also appear outside of math.SE (e.g. on the hot network questions), on sites that don't have MathJax enabled. Any non-basic uses of MathJax in the title will result in the title being hard to read on those sites. – celtschk Jan 17 '17 at 7:05
• That's a good point and I sometimes brought it up myself in favor of not using too much MJ in titles. Yet, by now, the HNQ is 'smart' regarding MJ and filters against MJ on non-MJ sites, that is, your particular example is not an example anymore. – quid Jan 17 '17 at 11:00
• Re: If I recall correctly, there is even a recommendation somewhere "Make your question your title." Probably this is mentioned in some other places too, but one of the most visible is probably the part about titles in both copies of "How to ask a good question?" Here is the older one and the more recent. – Martin Sleziak Jan 23 '17 at 7:02
• @MartinSleziak yes, that's what I likely had in min. MO earlier had a similar recommendation, which may in turn have been similar to one on SO. On MO at some point it became "Make your title your question (But don't forget to restate it in the body!)" Maybe we could do this here too. – quid Jan 23 '17 at 11:04
• One of the links I've added (the one which is tagged faq) contains: "Your question should be clear without the title ... make sure that the question body does not rely on specific information in the title." So it is there. (I am not sure, perhaps it might be more prominently visible. However, to me the faq entry seems to be quite well written.) – Martin Sleziak Jan 23 '17 at 11:11
• @MartinSleziak right, as many it is to be assumed I did not read until the end. :-) I do not disagree that it is well-written. But I still think it could make sense to have these two pieces of information closer together. But maybe this is a discussion for elsewhere. – quid Jan 23 '17 at 11:34