User:Deskana (WMF)/Search/Interwiki

The problem

 * Search infrastructure and performance has been improved such that interwiki search is once again a possibility to have on the Wikimedia wikis.
 * How is this feature to be handled from a product perspective? For example, do we integrate into the current search, or do we have a separate interwiki search?

High-level user requirements

 * A keyword search should present the user with any relevant matches, both on their current wiki and any particularly relevant results from other Wikimedia wikis.

Current process
A person searches for keyword x on a Wikimedia wiki. There are several possibilities:
 * 1) There is no article with that title on any Wikimedia wiki.
 * 2) There is no article with this title on the wiki they're currently looking at, but there is an article on another wiki (or multiple wikis).
 * 3) There is an article with that title on their current wiki, but no exact matches on other wikis.
 * 4) There is an article with that title on their current wiki, but there are also exact matches on other wikis.

Currently, 1. and 2. result in a page telling the user their current wiki has no article, and offer a search page for the search term, and make no reference to other wikis. Similarly, 3. and 4. simply take the user to article on their current wiki, also with no reference to other wikis.

Random notes
Worth considering whether search should work the same across different namespaces.