Should we really encourage cross-posting?

Question

Cross-posting is strongly discouraged on some Stack Exchange sites, such as SoftwareEngineering.SE. There:

• If the question appears to belong to another site (which happens quite often with questions which should be on Stack Overflow), users vote for the question to be migrated if its quality is good enough (or closed otherwise).

• If the question is already posted by the same member on Stack Overflow, the author receives a comment explaining that he shouldn't cross-post. This, usually, follows by a lot of downvotes and close votes (although it may be that people who cross-post there are also often the ones who write bad questions in the first place).

I see that there is an opposite practice here, especially in relation to the questions about Arduino. Example:

Ask on SE.Ardruno, not here.

Is this an official practice here?

If not, would it be possible to stop inviting the users to cross-post, as the same users may then cross-post on other sites where the practice is discouraged?

Answer 1

Two separate issues here: that comment, and cross-posting in general.

As to the former - that comment is not an invitation to the user to cross-post their question. It's a comment indicating that the question is off-topic here and should/will be closed; if the asker chooses to re-post it on a site where it is on topic, that's fine - that's not cross-posting, because the question is only active on one site. It's also not possible here for questions to be migrated - there are no migration paths defined for regular users to use, so migrations can only be performed for exceptional cases by moderators.

In terms of cross posting in general - cross posting is allowed on the Stack Exchange network; what's discouraged is the shotgun approach - posting an identical question on as many sites as possible in an effort to just get an answer, any answer. Cross-posting because you're interested in an answer from two different perspectives, or because you want to know about two different facets of the answer, is fine so long as your question is tailored to each site you post it on. It's also generally recommended to cross-link the questions so someone doesn't discover it later and think you've done it disingenuously.