Anonymity, ephemerality, and hyper-locality are an uncommon set of features in the design of online communities. However, these features were key to Yik Yak's initial success and popularity. In an interview-based study, we found that these three features deeply affected the identity of the community as a whole, the patterns of use, and the ways users committed to this community. We conducted interviews with 18 Yik Yak users on an urban American university campus and found that these three focal design features contributed to casual commitment, transitory use, and emergent community identity. We describe situated anonymity, which is the result of anonymity, ephemerality, and hyper-locality coexisting as focal design features of an online community. This work extends our understanding of use and identity-versus-bond based commitment, which has implications for the design and study of other atypical online communities.

Online dating sites have become a common means of finding a romantic partner. And yet, these sites differ greatly from many other socially oriented websites: perhaps most notably, the pairwise style of interaction afforded by these sites prevents a robust online community from forming. Users, however, have taken matters into their own hands by creating thriving external forums for discussion of specific dating sites. We report on a multiple methods study of two online dating services, via observation and interviews with users of the forums associated with these sites. Our findings suggest that these forums play an essential role in creating an "outsourced community" for the dating sites, and also reveal practices around how some users "game the system" in online dating, the prevalence of harassment in online dating, and users' frustrations with current dating sites. We conclude with a number of recommendations for system design.

This paper presents a study of Nextdoor, a social media system designed to support local neighborhoods. While not the first system designed to support community engagement, Nextdoor has a number of attributes that make it distinct. Our study, across three communities in a major U.S. city, illustrates that Nextdoor inhabits an already-rich ecosystem of community-oriented social media, but is being appropriated by its users for use in different ways than these existing media. Nextdoor also raises tensions in how it defines the boundaries of neighborhoods, and in the privacy issues it raises among its users.