What's the Idea?
If a user tries to tag a Stack Overflow question with a tag that is used frequently on one of the sites that is closely related (DBA, Programmer, etc.) the tag should show up with the suggestion that the question belongs on Site X.
This would mean that if I start typing
Index on SO as a tag, it would tell me that the question might belong on DBA, and if I type
indexed-view, it almost certainly should be moved, since the tag exists on DBA but not SO. This would be especially useful for these tags that do not exist on Stack Overflow, but are on these other sites - so the site would need to track these. (More on this later.) This is not forced migration, but if a user types a tag that makes it seem likely that the question belongs elsewhere, we should tell them beforehand, not afterwords.
What would this look like?
The tags could be displayed in a new color, with a box suggesting migration, and if tags that don't exist on the current site, but are on one of the suggested migration sites are put into the tag list, they would only be allowed to post if they had a reputation above X or removed the tag (The tag-creation limit is probably the right number, but the warning should stay even for them.) This would look like the popup suggested here: http://meta.stackexchange.com/a/101231/187896
Which Tags Should be Picked?
There are a number of sites now, and obviously
Android on Science Fiction and Fantasy is not the same as
Android on Stack Overflow. The tags that are recommended for this would need to be more specific in how they find overlap.
Options: (Pick all that are correct)
- Finding which sites questions have already been migrated to, and picking all tags applied to a significant share of the questions moved to that site.
- Pick the top tags of questions that were moved to each site, ordered by the percentage of questions with that tag in the past year that were moved.
- Automatically use tags that were applied to some percentage of previously moved questions after the move.
- Allow moderators to manually add tags to this list.
Even an initial pass of the top 100 moved question tags could have a significant benefit to direct the users to the correct site. The list of tags that are used for this could be updated monthly or weekly, so that it's not constantly changing - and if it seems to be changing frequently, the choice methodology can be re-assessed.
Is this a Dupe?
I think not.
Similar things have been discussed here: This question may belong to <Another site>, consider migrating - this addresses some issues pointed out in the answers there, like upkeep costs, ongoing calculations, and specific ideas on how to select the tags.
Also these were mentioned, but this would be different, and I think it would be less effort to upkeep and implement. See here: Suggest community wiki based on title keywords, tags and here: Suggest community wiki based on title keywords, tags.