Research:How does communication/socialization affect newcomer retention?
(RQ2.1) Which cohorts of editors are communicating with newbies? ...what types of communication is common?
(RQ2.2) How does being welcomed affect newbie retention?
(RQ2.3) What's the impact of templates, positive or negative, on new users? ...how do newbies judge their tone?  found that welcome templates do more harm than good in WikiProjects. Personalized messages, on the other hand, were helpful.
(RQ2.4) How does being warned affect newbie retention? ...for different types of warnings (different templates, manual warnings, etc.)?
(RQ2.5) How likely are new users to receive warnings?
(RQ2.6) What percentage of edits to new editor talk pages are notices of speedy deletion? ...has this number changed since CSD notices were created? We have evidence from EN wiki that new editors whose articles are speedy deleted are unlikely to stay; Do other language wikis have the same pattern? [who, where?]
(RQ2.7) How does praise or other positive reinforcement affect new user retention?
(RQ2.8) How has the amount of praise changed over the years of the projects?
(RQ2.9) How does nomination for DYK affect new user retention?
(RQ2.10) What kinds of editors tend to welcome or offer praise to newbies?
(RQ2.11) How do mentoring programs (eg. German, Adopt-a-user, etc.) affect the work of newbies and retention?
(RQ2.12) What are the growth trends in terms of mentors/mentees?
(RQ2.13) How many users who have participated in the mentoring program stay on as long term editors?  finds that the Adopt-a-user program doesn’t make any measurable difference and attributes this to a failure of consistency and relevance. For example, many people join the mentoring program as mentees after they have gotten too much experience to find it useful.
(RQ2.14) How many mentor/mentee interactions typically take place?
(RQ2.15) How do edit characteristics of mentored users differ from non-mentored users?
(RQ2.16) How are new editors currently asking for assistance?
Social Graph and Impact on Participation
(RQ2.17) How does the overall level of user-to-user interaction correlate with long-term participation? E.g., comparison of social graph of experienced editors: how does social graph of heavy main namespace editors compare with that of light main namespace editors? For those same light and heavy editors, what was the velocity of change in their social graph during the first few weeks of editing?
- Choi et al., Socialization tactics in Wikipedia and their effects. http://dx.doi.org/10.1145/1718918.1718940
- Musicant et al. (Outcomes of Wikipedia’s mentoring program). Under Review, 2011.