== Background
Prior to deployment, we would like to complete the analysis of the page previews a/b test for page previews.
== Acceptance criteria
- Repeat the analysis from {T139319}/{T145770} for the A/B test on enwiki and dewiki from October/November 2017
- Report feature performance cumulative and per-wiki:
-- Difference in pageviews per session --> T182314#3896974
-- Difference in page interactions (pageviews + previews) per session
-- Average cards viewed per page --> T182314#3901330
-- Average cards viewed per session --> T182314#3901330
-- Rate of accidental card views
-- Disable rates --> T182314#3901330
-- Usage of back button (cf. T144603)
-- Nice to have: Effects on "reading depth" (i.e time spent per page, from [[https://meta.wikimedia.org/wiki/Schema:ReadingDepth|the ReadingDepth schema]])