Planet Hunters and Seafloor Explorers: Legitimate Peripheral Participation Through Practice Proxies in Online Citizen Science Gabriel Mugar,* Carsten Østerlund,* Katie DeVries Hassman,* Kevin Crowston,** Corey Brian Jackson* *Syracuse University, School of Information Studies; 337 Hinds Hall, Syracuse, New York, 13244 {gmugar, costerlu, klhassma, cjacks04}@syr.edu **National Science Foundation; 4201 Wilson Boulevard Room 1125, Arlington, Virginia, 22230 kcrowsto@nsf.gov ABSTRACT Making visible the process of user participation in online crowdsourced initiatives has been shown to help new users understand the norms of participation [2]. However, in many settings, participants lack full access to others’ work. Merging the theory of legitimate peripheral participation [18] with Erickson and Kellogg’s theory of social translucence [10, 11, 16] we introduce the concept of practice proxies: traces of user participation in online environments that act as resources to orient newcomers towards the norms of practice. Through a combination of virtual [14] and trace ethnography [12] we explore how new users in two online citizen science projects engage with these traces of practice as a way of compensating for a lack of access to the process of the work itself. Our findings suggest that newcomers seek out practice proxies in the social features of the projects that highlight contextualized and specific characteristics of primary work practice. Author Keywords Situated Learning; Social Translucence; Legitimate Peripheral Participation; Socialization; Citizen Science ACM Classification Keywords H.5.2 [Information Interfaces and Presentation]: User Interfaces - Interaction styles. General Terms Human Factors; Design; Measurement. INTRODUCTION To sustain a group over time, its newcomers must learn to become effective participants. In some groups, new members go through formal educational or orientation activities in order to learn group practices. However, researchers have argued that formal education alone does not convey the necessary tacit knowledge about work practices needed for good performance. Such tacit knowledge can be conveyed instead through informal learning experiences, such as through legitimate peripheral participation (LPP), a process of situated learning whereby newcomers initially engage in simple practices while observing the work practices and behavior of more experienced members of a community [18]. Online groups present more challenges to newcomer orientation. Many online groups are composed of members who are not part of a single formal organization and who contribute only in their free time, reducing or eliminating the possibility of formal training. However, the affordances of the technologies used to support group interactions often make it possible for distributed volunteers to observe work in progress, thus enabling a form of LPP. For example, Bryant et al. [2], studied new Wikipedia participants and suggested that new editors begin by reading articles before they make their initial contributions. In this paper, we examine newcomer learning in online citizen science projects: non-temporary groups in which large numbers of distributed volunteers collaborate with domain scientists to collect, annotate, identify and analyze items in large data sets to fulfill scientific goals. These projects are an intriguing example of distributed learning and knowledge production supported by public engagement in scientific research processes [15, 26]. Specifically, we examined two projects developed as part of Zooniverse 1 : Planet Hunters (PH) and Seafloor Explorer (SE), in which members of the general public are asked to annotate scientific data (identifying evidence of possible planets and marine organisms, respectively). To be effective over time, the projects must facilitate the orientation of new users to the goals and work practice of the project. However, unlike other online projects like Wikipedia, PH and SE participants are not able to see the work other users have done, in this case, the primary annotations they have made. 1 https://www.zooniverse.org/ (c) 2013 Association for Computing Machinery. ACM acknowledges that this contribution was authored or co-authored by an employee, contractor or affiliate of the United States government. As such, the United States Government retains a nonexclusive, royalty-free right to publish or reproduce this article, or to allow others to do so, for Government purposes only. CSCW'14, February 15 – 19, 2014, Baltimore, MD, USA. Copyright 2013 ACM 978-1-4503-2540-0/14/02…$15.00. http://dx.doi.org/10.1145/2531602.2531721 CSCW 2014 • Blinding me with Science February 15-19, 2014, Baltimore, MD, USA 109