Should we close questions that are exact duplicates of open ELU questions?

Question

Recently one user posted this question (Is this an inversion or other construction?), however it is an almost exact duplicate of this question on ELU:

In my opinion questioners should ask their question on either ELU or ELL, but not both. My rationale is thus:

1. There is significant cross-over from ELL and ELU in terms of our answerers. Asking questions on both sites therefore doubles the work for answerers.

2. It is disheartening for an answerer to answer the question, only to see that their hard work answering was unnecessary, since the question has already been answered verbatim elsewhere. This wastes valuable answerer time.

3. Discussions, comments and so on that are attached to one question don't get attached to the other - making it harder for the two posts to remain consistent.

4. Once the question has been answered on both sites, there is a conflict - which is the better answer? The two sites could have entirely conflicting "preferred answers".

My suggestion then is this

Questions that are asked on ELU and again verbatim on ELL (whilst the question is still open on ELU) should be closed as "not constructive" immediately, unless the question clearly distinguishes why the asker would like to ask both communities.

For example, the following is OK:

Do you put a space before punctuation in English? I'm an English teacher and I need to know the basic answer for my students, but I'm also interested in a more in-depth answer about under what circumstances this "rule" can be broken as well.

ELL answer: No. Punctuation has no prefix space and one suffix space (except for open-parentheses which are one prefix, no suffix). Always put punctuation in the right places or your essays will come back with lots of red ink on them and you will get bad marks in exams.

ELU answer: As the ELL answer, but here are some interesting old fashioned bits of text showing that it used to be different, some talk about fonts and why double spaces after punctuation is generally discouraged, and perhaps a slight discourse on how some editors prefer the old way.

The following is not OK:

What does this sentence mean: "It's raining cats and dogs"?

ELU answer: It means it's raining a lot. BTW, why are you asking the same question on ELL?

ELL answer: It means it's raining a lot. BTW, someone on ELU has already answered your question.

On this question, vote up if you agree that we should close such questions, or vote down if you think we shouldn't.

Answer 1

This question has been asked on MSO, and Jeff Atwood gave a rather definitive response:

Cross-posting questions is strongly discouraged. See

Is it possible to post questions across a couple of the sites because it's debatable which site it fits best?

Allowing cross-posting is a slippery slope.

If you might have slightly better odds of getting an answer by posting it on two sites, well, by gum, why not maximize your odds by posting it on twenty sites!

There are some questions which fall into grey areas between sites, and I think it's OK to ask and delete, then re-ask if you feel you have asked on the wrong site.

But as a general rule, do not cross-post questions, please. Pick a site and go with it.

It is also ok to ask two different versions of a question but you MUST tailor it to the audience on that site. Copying and pasting would put you on the road to account suspension.

So, it seems the answer is clear; if you cross-post a question it must be tailored to the site, the idea behind which seems to be that you're expecting a different answer from the users on each site. That doesn't, in general, seem to be the case in the questions we've seen cross-posted between ELL and ELU; the goal simply seems to be to reach a wider audience in hopes of achieving a single answer. So these question should certainly be closed.

The concept behind not cross-posting is the same concept behind not asking duplicate questions; you don't want to separate the content up between multiple places. You want all the answers to be found in one place. If a question is on-topic on multiple sites (which can happen) you simply choose what you think is the best site and ask it there. Cross-posting shouldn't usually be necessary.

Answer 2

In some question about cross-posting questions, Jeff Atwood says that questions asked on different sites should be tailored for the specific site; that means I should not ask the same exact question on two different sites, but I should ask on different aspects.

In our case I would also add that a question should not be asked on ELL and EL&U if it would get the same answer. For example, if I asked on EL&U what the indefinite article is (supposing it would not get closed as general reference), I would not ask the same question also on ELL, since the answer would not change.
Probably, there are questions that on ELL would get a different answer, possibly because the users who answer keep in consideration the fact the question is asked from an English learner, not a serious English language enthusiast.

As for the closing reason, questions that are asked verbatim on Stack Overflow and Drupal Answers are closed as off-topic even if they are not really off-topic. Probably in our case off-topic would give the wrong message, but I guess that also other closing reasons could be misunderstood, since there isn't a closing reason for questions that are cross-posted.

Answer 3

It's relevant to note that the specific "duplicate" examples cited by OP here were both posted by the same user, several months apart, on two different SO sites.

I don't claim my own answer on ELL is "definitive", nor do I have any serious issues with the ELU answer. But if we accept the basic premise that ELL should/could be a viable site of its own, then if a question is On Topic here, we shouldn't close it simply because the same or similar has been asked on ELU.

Because the ELL question has been summarily/meaninglessly closed as Off Topic, it's not possible for anyone else to post a better answer than my own. Which strikes me as slightly ridiculous, given that the questioner (who incidentally has posted many useful/searching questions here on ELL) clearly didn't get exactly what s/he wanted from the ELU answer (or, possibly, from the sole ELL answer available).

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TL;DR: Questions on ELL should be judged on their own merits, and thus should not be closed simply because they've been asked elsewhere. Since ELL aspires to differentiate itself from ELU, we should keep questions like the case in point open and active. With any luck we'll eventually be able to show answers that target the issues better from a learner's perspective.

ELL desperately needs a valid raison d'être. Closing that question gives me the impression it's being seen as an "overspill" site for ELU, which I think is not good for business.