Based on the finalized design from T146663 and T139310, this A/B test will have a test group that will be shown additional information that will be relevant to individual results on the existing search results page. This additional information will be links and metadata of //related pages// with links to //related categories// and //suggested language links// that are similar to the individual search results. A control group will see the currently existing search results page.
> This test is expected to last a week and will probably be run on English Wikipedia (desktop only) in June 2017. We'll use this ticket for the gerrit code check-ins and for turning the test on and off.
**Test group users will see for each search result returned**:
* 'explore similar' link and dropdown icon
* when the user hovers over the link of the search result, we will roll down a display below the result:
* a label '**Related pages**' and
** up to 3 related page links containing metadata (as available):
*** thumbnail image
*** name of related pages
*** metadata description
* a label '**Categories**' and
** a 3 column listing of links
*** up to 3 links of related categories per column (for a maximum total display of 9 related categories)
* a label '**Suggested languages**'
** display of additional languages that the article is available in
** this uses the preferred browser language settings and the regional languages (using the universal language selector - user's IP region, browser preferred lang and the lang that the user has set as preferred within the Wikipedia account UI)
* when the user moves away from the new box, the links will roll back up
* if there aren't any articles in different languages, message that and add a link to translatewiki
**Bucket testing** logic //generally// is as follows:
- 1 in 1000 users are included in EventLogging (on enwiki that's about 2K full-text searchers, according to T163273)
- Of those 1 in 1000 users, 1 in 2 are included in the test
- Of those 1 in 2 users
-- 50% go in a **test** group, labeled "serp_explore_similar"
-- the other 50% of users will go in a **control** group, labeled "serp_no_similar_links"
- The remaining chunk (~1K) of the original bucketed ~2K users will get a NULL (the string null, or the MySQL null, we can detect either).
**Eventlogging** needs to capture:
* if the user hovered over the 'explore' links (to open the listings)
* if results for related pages were shown and how many
* if results for related categories were shown and how many
* if results for languages were shown and how many
* if the user clicked on a related page and which one
* if the user clicked on a related category and which one
* if the user clicked on a language link and which one
* we'd like to know if overall clicks go up or down for the search results