== Test principles ==
**We will include all contributors in the A/B test who:**
- Do not have a sticky preference set
- Have made <100 overall edits
- Are anonymous or registered users
**Bucketing criteria**
The first time we see an anonymous user, we should use client-side logic to randomize them into either bucket and then set a cookie so that every EditAttemptStep event sent from them includes the appropriate value in the “cohort” field. If we’re doing this for anonymous editors, we should do it the same way for registered users as well.
**Storing persistent identifiers for bucketed anons**
We have to run test and conduct analysis within 90 days of test start date. We could use IP address + user agent as the ID, or create and store our own (more robust but harder and probably not worth the effort).
###Research questions*
//Does VE being the default mobile editing interface...//
- Increase edit completion rate?
- Increase the number of successful edits contributor make over a tbd period of time?
- Increase editor retention?
- Increase the number of switched-editor-type actions? (I.e. people fleeing back to wikitext.)
*See T221187
###Blocking questions
- [ ] Can we use cookies for anons? How would we store a persistent identifier for bucketed anons?
###Open questions
- [x] Under what conditions are contributors' editing interface preferences set? See T221195#5201746
- [ ] How will we bucket users if we want to include contributors who are not logged in?
- [ ] What level of precision is appropriate for this A/B test?
- [ ] What wikis are being included in this A/B test? See T222803
- [x] Confirm: we can distinguish between contributors who do and do not have a sticky editing interface preference set? **Yes**
- [ ] Confirm: what impact – in terms of scale – does including all contributors who do not have a sticky preference set on the number of edit sessions
- [ ] How long will the test last?
- [ ] How are we going to monitor the test? What will trigger us to interrupt the test?
- [ ] What are the range of actions we could take after the test concludes? What will determine which action(s) we take?
- [ ] What could we do to exclude editors from our edit completion rate numbers who we assume do not have any intention of completing an actual edit?
###"Done"
- [ ] A phabricator task is created that specifies how engineering should implement/instrument the A/B test