Online communities offer their members various benefits, such as information access, social and emotional support, and entertainment. Despite the important role that founders play in shaping communities, prior research has focused primarily on what drives users to participate and contribute; the motivations and goals of founders remain underexplored. To uncover how and why online communities get started, we present findings from a survey of 951 recent founders of Reddit communities. We find that topical interest is the most common motivation for community creation, followed by motivations to exchange information, connect with others, and self-promote. Founders have heterogeneous goals for their nascent communities, but they tend to privilege community quality and engagement over sheer growth. Differences in founders’ early attitudes towards their communities help predict not only the community-building actions that they pursue, but also the ability of their communities to attract visitors, contributors, and subscribers over the first 28 days. We end with a discussion of the implications for researchers, designers, and founders of online communities.

Volunteer moderators are an increasingly essential component of effective community management across a range of services, such as Facebook, Reddit, Discord, YouTube, and Twitch. Prior work has investigated how users of these services become moderators, their attitudes towards community moderation, and the work that they perform, largely through interviews with community moderators and managers. In this paper, we analyze survey data from a large, representative sample of 1,053 adults in the United States who are active Twitch moderators. Our findings -- examining moderator recruitment, motivations, tasks, and roles -- validate observations from prior qualitative work on Twitch moderation, showing not only how they generalize across a wider population of livestreaming contexts, but also how they vary. For example, while moderators in larger channels are more likely to have been chosen because they were regular, active participants, mods in smaller channels are more likely to have had a pre-existing connection with the streamer. We similarly find that channel size predicts differences in how new moderators are onboarded and their motivations for becoming moderators. Finally, we find that moderators' self-perceived roles map to differences in the patterns of conversation, socialization, enforcement, and other tasks that they perform. We discuss these results, how they relate to prior work on community moderation across services, and applications to research and design in volunteer moderation.

Many types of online communities rely on volunteer moderators to manage the community and maintain behavioral standards. While prior work has shown that community moderators often develop a deep understanding of the goals of their moderation context and sophisticated processes for managing disruptions,less is known about the processes through which moderators develop this knowledge. In this paper, we leverage Donald Schön's concept of reflective practice as a lens for exploring how community moderators develop the 'knowledge-in-action' that they use to perform their work. Drawing on interviews with 18 Twitch moderators, we conceptualize moderators as reflective practitioners, iteratively encountering novel situations and adjusting their practices and mental models. Our findings provide detailed insight into how community moderators reflect-in-action, re-evaluating in real-time their mental models of viewer intent and community goals, and reflect-on-action, conducting post hoc assessments of individual incidents and long-term changes to adjust their practice over time. Moderators working in teams reveal specific aspects of reflection facilitated by cooperative discussion, which we call 'groupwise reflective practice'. By identifying community moderation as a form of reflective practice, we can leverage insights gained from studying practitioners in other fields,providing theoretical and practical implications for the study and support of community moderation.

Participation in communities is essential to individual mental and physical health and can yield further benefits for members. With a growing amount of time spent participating in virtual communities, it's increasingly important that we understand how the community experience manifests in and varies across these online spaces. In this paper, we investigate Sense of Virtual Community (SOVC) in the context of live-streaming communities. Through a survey of 1,944 Twitch viewers, we identify that community experiences on Twitch vary along two primary dimensions: belonging, a feeling of membership and support within the group, and cohesion, a feeling that the group is a well-run collective with standards for behavior. Leveraging the Social-Ecological Model, we map behavioral trace data from usage logs to various levels of the social ecology surrounding an individual user's participation within a community, in order to identify which of these can be associated with lower or higher SOVC. We find that features describing activity at the individual and community levels, but not features describing the community member's dyadic relationships, aid in predicting the SOVC that community members feel within channels. We consider implications for the design of live-streaming communities and for fostering the well-being of their members, and we consider theoretical implications for the study of SOVC in modern, interactive online contexts, particularly those fostering large-scale or pseudonymized interactions. We also explore how the Social-Ecological Model can be leveraged in other contexts relevant to Computer-Supported Cooperative Work (CSCW), with implications for future work.

Accounts of the social experience within livestreaming channels vary widely, from the frenetic "crowdroar" offered in some channels to the close-knit, "participatory communities" within others. What kinds of livestreaming communities enable the types of meaningful conversation and connection that support relationship development, and how? In this paper, we explore how personal relationships develop within Twitch, a popular livestreaming service. Interviews with 21 pairs who met initially within Twitch channels illustrate how interactions originating in Twitch's text-based, pseudonymous chat environment can evolve into close relationships, marked by substantial trust and support. Consistent with Walther's hyperpersonal model, these environments facilitate self-disclosure and conversation by reducing physical cues and emphasizing common ground, while frequent, low-stakes interaction allow relationships to deepen over time. Our findings also highlight boundaries of the hyperpersonal model. As group size increases, participants leverage affordances for elevated visibility to spark interactions; as relationships deepen, they incorporate complementary media channels to increase intimacy. Often, relationships become so deep through purely computer-mediated channels that face-to-face meetings become yet another step in a continuum of relationship development. Findings from a survey of 1,367 members of Twitch communities demonstrate how the suitability of these spaces as venues for relational interaction decreases as communities increase in size. Together, these findings illustrate vividly how hyperpersonal interaction functions in the context of real online communities. We consider implications for the design and management of online communities, including their potential for supporting "strong bridges," relationships which combine the benefits of strong ties and network bridges.

We pose a fundamental question in understanding how to identify and design successful communities: What factors predict whether a community will grow and survive in the long term? Social scientists have addressed this question extensively by analyzing offline groups which endeavor to attract new members, such as social movements, finding that new individuals are influenced strongly by their ties to members of the group. As a result, prior work on the growth of communities has treated growth primarily as a diffusion processes, leading to findings about group evolution which can be difficult to explain. The proliferation of online social networks and communities, however, has created new opportunities to study, at a large scale and with very fine resolution, the mechanisms which lead to the formation, growth, and demise of online groups.