Recently, I made a comment here that, for this particular question, given the tags (the tags were there before the edit occurred), it is clear what the context should be. However, one of the people responding to my comment disagreed.

As another example, suppose someone asked me how to show $\lim\limits_{x \to 3}x = 3$.

If I saw as the only tag for this question, I probably wouldn't talk about $\delta$-$\epsilon$ or even plugging in the value for $x$ due to continuity (unless they mention otherwise that they've learned about continuity). Instead, I would focus on graphical intuition.

If I saw as one of the tags (N.B.: not the only tag), I would mention continuity and the theorem that you can plug in values due to polynomials being continuous.

If I saw as one of the tags, I would probably mention doing a $\delta$-$\epsilon$ proof (unless otherwise desired).

What says the community? If a question is asked perfectly well, are tags enough to contextualize a question?

The reason why I am concerned about this in the first place is that - in my opinion - we can't expect each user of this site to know their topics on which they have questions in the utmost generality, and if they've asked their question well, with appropriate tags, in the majority of cases, that should be enough to understand the question (and to not mark it to be closed for lack of context).

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    $\begingroup$ For what it's worth, I just saw a question on MO about high school algebra homework, with the tag, central-simple-algebras. $\endgroup$ Jun 17, 2016 at 0:02
  • $\begingroup$ I think $\lim$ barely makes sense without knowledge of $\epsilon-\delta$. Also, I really don't believe there is a "calculus vs real analysis" dichotomy, I would say "real analysis" is a rather sophisticated branch of calculus, which however doesn't mean there should be any less rigour in calculus than in real analysis. $\endgroup$
    – Vim
    Jun 17, 2016 at 11:41
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    $\begingroup$ "With all other variables held constant [...]". With this phrasing, it is easy to guess which Stack Exchange meta site we are on :) $\endgroup$
    – Therkel
    Jun 18, 2016 at 14:03
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    $\begingroup$ $\text{lim}$ can be defined purely based on topology, with no use of epsilons or deltas... $\endgroup$
    – Nick Alger
    Jun 19, 2016 at 19:35

1 Answer 1


I would generally say that it is preferable that the body of the post contain all the relevant information, with the tags and the title not being necessary to understand the question. It seems that, even in cases where the tags suggest certain interpretations, an answerer still has to guess at context until something more explicit is written. This is especially true since authors may not be familiar enough with the tags and their implications to properly tag their questions.

In cases where the tags imply something not stated, one can leave a comment suggesting this interpretation and asking for clarification. This is exactly what comments are for, and seems to be what successfully played out in the question you linked to. One could also make edits to the question if they're sure what the author's intention was.

I can imagine a question asking for $\varepsilon\!-\!\delta$ proof of a limit posting under any of the tags you mention (even if inappropriately), or a question wanting graphical intuition showing up under . Plus, it's always possible that the author was only introduced to some less common formulation of limits, but isn't aware of it. In any of these cases, we get a clearer picture of the question by using comments to ask for the particular definitions in play. The tags can help guide comments to more specific suggestions of, "I assume you mean ____. Is that what you're after?"

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    $\begingroup$ Indeed, where I'm forced to make an interpretation based on tags alone, I first leave a Comment asking, then go back hours later and vote to close if no clarification is forthcoming. $\endgroup$
    – hardmath
    Jun 17, 2016 at 5:33
  • $\begingroup$ @hardmath That is harsh to vote to close because a user has not yet replied... $\endgroup$
    – user64742
    Jun 25, 2016 at 20:52
  • $\begingroup$ @TheGreatDuck: When a Question is placed on-hold/closed, Editing the Question automatically puts the post into the Reopen review queue. So a vote to close for being unclear (not "because a user has not yet replied") is not the final disposition. $\endgroup$
    – hardmath
    Jun 25, 2016 at 21:00
  • $\begingroup$ @hardmath i mean that ansking for clarification and then getting impatient and voting to close is harsh. $\endgroup$
    – user64742
    Jun 25, 2016 at 21:07

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