From the 2017-18 quarter one goals: https://www.mediawiki.org/wiki/Wikimedia_Audiences/2017-18_Q1_Goals#Readers
"Finish up testing of the Explore Similar feature on search results page; analyze data and gather community feedback; request internationalization strings; deploy feature"
I'll help where needed in working with the communities and product teams for this goal.
I helped provide some feedback on consistency of the sister-search-results. In particular the labels for sister search results were improved on English Wikipedia with the assistance of a few community members. Many thanks.
https://en.wikipedia.org/wiki/MediaWiki_talk:Search-interwiki-custom
https://phabricator.wikimedia.org/T171804#3524623
As other search-improvement tests did not proceed to production my role was limited.