Hi,
It looks like a very long-awaited may be coming to Wikimedia projects soon: search results from other languages will be shown.
It happens very frequently that people search in language X while looking at a Wikipedia in language Y. For example, they search in Russian while looking at the English Wikipedia. Currently it fails, because search is limited only to one language.
For years I have been raising this issue with the Foundation's management, and it looks like this is going to be addressed.
Wikimedia's search team (also known as Discovery) has already enabled showing results from other Wikimedia projects near the search results, for example showing results from the English Wikisource in the sidebar of the search results of the English Wikipedia. It is now experimenting with showing results from other languages.
Currently it looks like the prioritized languages will be the same as the languages that are suggested by UniversalLanguageSelector, namely the language of the browser and the operating system, previously clicked languages, and languages found by geolocation. This may be tweaked in the future.
Note that this is not being developed by the Language team in the Foundation, but by the Search team.
You can read more about it at: https://www.mediawiki.org/wiki/Cross-wiki_Search_Result_Improvements/explore...
and there's a demo at: http://sistersearch.wmflabs.org/w/index.php?search=~rainbow&title=Specia...
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