Comparison of user retention between control and treatment group is one of the primary metrics for MinT for Wiki Readers experiment (WE 3.1.1 for FY25/26). We will need additional instrumentation to track, and monitor this as part of the xLab Automated Analytics. The following actions to be instrumented:
When subject from either control or treatment visits any page
```
action: page_visited
action_subtype: initial_visit
```
When the subject visits and scrolls (the first time)
```
action: page_scrolled
action_subtype: initial_scroll
```
When the subjects visits and stays for at least 3 seconds (in visible state)
```
action: page_visited
action_subtype: visited_3secs
```
The primary page visit event is the important one, and the other two can considered if time and bandwidth permits. The events can be sent to the same stream: `mediawiki.product_metrics.translation_mint_for_readers` and the latest schema version: `/analytics/product_metrics/web/translation/1.4.2`.
The code will be part of [[ https://www.mediawiki.org/wiki/Extension:WikimediaEvents | WikimediaEvents extension ]] and for reference this is the [[ https://gerrit.wikimedia.org/r/plugins/gitiles/mediawiki/extensions/WikimediaEvents/+/87f4762ec1c4a9e50df02fe62d60b791481de5ea/modules/ext.wikimediaEvents/xLab/pageVisit.js | PageVisit ]] instrument used for Synthetic A/A test.