Applications in a range of domains, including route planning and well-being, offer advice based on the social information available in prior users' aggregated activity. When designing these applications, is it better to offer: a) advice that if strictly adhered to is more likely to result in an individual successfully achieving their goal, even if fewer users will choose to adopt it? or b) advice that is likely to be adopted by a larger number of users, but which is sub-optimal with regard to any particular individual achieving their goal? We identify this dilemma, characterized as Goal-Directed vs. Adoption-Directed advice, and investigate the design questions it raises through an online experiment undertaken in four advice domains (financial investment, making healthier lifestyle choices, route planning, training for a 5k run), with three user types, and across two levels of uncertainty. We report findings that suggest a preference for advice favoring individual goal attainment over higher user adoption rates, albeit with significant variation across advice domains; and discuss their design implications.

Maintaining participation beyond the initial period of engagement is critical for peer production systems. Theory suggests that an increase in motivation is expected with contributors' movement from the community periphery to the core. Less is known, however, about how specific motivations change over time. We fill this gap by focusing on individual motivational paths in the formative periods of engagement, exploring which motivations change and how. We collected data on various instrumental and non-instrumental motivations at two points in study participants? Wikipedia career: when they started editing and again after six months. We found that non-instrumental motivations (including collective and intrinsic motives) decreased significantly over time, in contrast with socially-driven motivations such as norm-oriented motivates which did not change and social motives which increased marginally. The findings offer new insights into newcomers' evolving motivations, with implications for designing and managing peer-production systems.

Research on peer-production suggests that as participants choose what actions to perform, prototypical activity patterns emerge. Recent work characterized these patterns and demonstrated that informal emergent roles are highly stable. Nonetheless, we know little about the ways in which contributors take on and shed emergent roles. The objectives of this study are to: (a) delineate the temporal dynamics of participants' emergent role taking behaviors, and (b) identify the motivations driving role-transition behaviors. Our study links motivation to role-transition behaviors within Wikipedia. Our first sample covered eleven years and 222,119 contributors, and was used to identify four categories of temporal role-taking behaviors, that differ in their mobility between emergent roles and across Wikipedia articles. Our second examination linked the motivations of 175 new participants to their subsequent role-taking activity over 14 months. Together, the two analyses reveal that role-taking categories can be distinguished based on participants' motivational orientation (intrinsic/extrinsic and self/others-oriented).

Peer production communities often struggle to retain contributors beyond initial engagement. This may be a result of contributors' level of motivation, as it is deeply intertwined with activity. Existing studies on participation focus on activity dynamics but overlook the accompanied changes in motivation. To fill this gap, this study examines the interplay between contributors' fun motives and activity over time. We combine motivational data from two surveys of Wikipedia newcomers with data of two periods of editing activity. We find that persistence in editing is related to fun, while the amount of editing is not: individuals who persist in editing are characterized by higher fun motives early on (when compared to dropouts), though their motives are not related to the number of edits made. Moreover, we found that newcomers' experience of fun was reinforced by their amount of activity over time: editors who were initially motivated by fun entered a virtuous cycle, whereas those who initially had low fun motives entered a vicious cycle. Our findings shed new light on the importance of early experiences and reveal that the relationship between motivation and participation levels is more complex than previously understood.

The increase in the availability of personal genomic data to lay consumers using online services poses a challenge to HCI researchers: such data are complex and sensitive, involve multiple dimensions of uncertainty, and can have substantial implications for individuals' well-being. Personal genomic data are also unique because unlike other personal data, which constantly change, genomic data are largely stable during a person's lifetime; it is their interpretation and implications that change over time as new medical research exposes relationships between genes and health. In this paper, we present a novel tool for self exploration of personal genomic data. To evaluate the usability and utility of the tool, we conducted the first study of a genome interpretation tool to date, in which users used their own personal genomic data. We conclude by offering design implications for the development of interactive personal genomic reports.

In this study we explore the impact of exposure to social annotation, embedded in online consent forms, on individuals' beliefs and decisions in the context of informed consent. In this controlled between-subjects experiment, participants were presented with an online consent form for a personal genomics study. Individuals were randomly assigned to either a social annotation condition that exposed them to previous users' comments on-screen, or to a traditional consent form without social input. We compared participants' perceptions about their consent decision, their trust in the organization seeking the consent, and their actual consent across conditions. While no significant difference was observed between actual consent rates, we found that on average individuals exposed to social annotation felt that their decision was more informed, and furthermore, that the effect of the exposure to social annotation was stronger among users characterized by relatively lower levels of prior privacy preserving behaviors.