Abstract: Micro-task markets such as Amazon’s Mechanical Turk represent a new paradigm for accomplishing work, in which employers can tap into a large population of workers around the globe to accomplish tasks in a fraction of the time and money of more traditional methods. However, such markets typically support only simple, independent tasks, such as labeling an image or judging the relevance of a search result. Here we present a general purpose framework for accomplishing complex tasks using micro-task markets. Our approach is inspired by the MapReduce framework for distributed processing and provides a scaffolding for complex human computation tasks. We describe our general framework, a web-based prototype, and case studies on article writing and decision making that demonstrate the benefits of the approach. This work has been funded in part by the National Science

When experts participate in collaborative systems, tension may arise between them and novice contributors. In particular, when experts perceive novices as a bother or a threat, the experts may express territoriality: behaviors communicating ownership of a target of interest. In this paper, we describe the results of a user study of a mobile social tagging system deployed within a museum gallery to a group of novices and experts collaboratively tagging part of the collection. We observed that experts express greater feelings of ownership towards their contributions to the system and the museum in general. Experts were more likely than novices to participate at higher rates and to negatively evaluate contributions made by others. We suggest a number of design strategies to balance experts’ expressions of territoriality so as to motivate their participation while discouraging exclusionary behaviors. Author Keywords Territoriality, experts, novices, collaboration

Volunteer computing is a powerful way to harness distributed resources to perform large-scale tasks, similarly to other types of community-based initiatives. Volunteer computing is based on two pillars: the first is computational – allocating and managing large computing tasks; the second is participative – making large numbers of individuals volunteer their computer resources to a project. While the computational aspects of volunteer computing received much research attention, the participative aspect remains largely unexplored. In this study we aim to address this gap: by drawing on social psychology and online communities research, we develop and test a three-dimensional model of the factors determining volunteer computing users ’ contribution. We investigate one of the largest volunteer computing projects –

Open contribution systems such as Wikipedia and Linux have been extraordinarily successful at eliciting contributions from many volunteers, but other projects struggle. While research has examined general motivations for contribution, we know little about what triggers contribution at a specific time. In this paper we mine the history of Wikipedia to understand the contribution process in the context of the many competing demands on users ’ attention at their computers. In particular, we examine the influence of the visible work of others on the timing and amount of contributions to Wikipedia. Using two different statistical models we show converging evidence of a substantial influence of others ’ visible work on triggering contribution. Author Keywords motivation, attention, contribution, online communities,

Online production systems represent a new and innovative approach for producing information goods. However, the success of such endeavors depends on a careful interrelationship between their social and technical dimensions. In this paper, we explore how various aspects of those dimensions impact the success of online production systems. We collected data from the open source community GNOME and we used the inclusion of a product into an official release as indicator for the success of a project. Our analyses revealed that structural characteristics of the individual project’s communication and task dependency (coordination needs) networks, the position of individuals in the overall ecosystem communication network as well as the technical structure of the product, are all significantly associated with project success. Our novel results represent an important step in understanding the success drivers of online production systems as well as a starting point for reshaping traditional models for producing information goods typically used in corporate settings.

In this paper we propose a theoretical framework to understand the governance of internet-mediated social production. Focusing on one of the most popular websites and reference tools, Wikipedia, we undertake an exploratory theoretical analysis to clarify the structure and mechanisms driving the endogenous change of a large-scale social production system. We argue that the popular transactions costs approach underpinning many of the analyses is an insufficient framework for unpacking the evolutionary character of governance. The evolution of Wikipedia and its shifting modes of governance can be better framed as a process of building a collective capability, namely the capability of editing and managing a new kind of encyclopedia. We understand Wikipedia evolution as a learning phenomenon that gives over time rise to governance mechanisms and structures as endogenous responses to the problems and conditions that the ongoing development of Wikipedia itself has produced over the years. Finally, we put forward five empirical hypotheses to test the theoretical framework.

Abstract. This paper investigates how Wikibooks authors collaborate to create high-quality books. We combined Information Retrieval and statistical techniques to examine the complete multi-year lifecycle of over 50 high-quality Wikibooks. We found that: 1. The presence of redundant material is negatively correlated with collaboration mechanisms; 2. For most books, over 50 % of the content is written by a small core of authors; and 3. Use of collaborative tools (predicted pages and talk pages) is significantly correlated with patterns of redundancy. Non-redundant books are well-planned from the beginning and require fewer talk pages to reach high-quality status. Initially redundant books begin with high redundancy, which drops as soon as authors use coordination tools to restructure the content. Suddenly redundant books display sudden bursts of redundancy that must be resolved, requiring significantly more discussion to reach high-quality status. These findings suggest that providing core authors with effective tools for visualizing and removing redundant material may increase writing speed and improve the book’s ultimate quality.

Online production groups have the potential to transform the way that knowledge is produced and disseminated. One of the most widely used forms of online production is the wiki, which has been used in domains ranging from science to education to enterprise. We examined the development of and interactions between coordination and conflict in a sample of 6811 wiki production groups. We investigated the influence of four coordination mechanisms: intra-article communication, inter-user communication, concentration of workgroup structure, and policy and procedures. We also examined the growth of conflict, finding the density of users in an information space to be a significant predictor. Finally, we analyzed the effectiveness of the four coordination mechanisms on managing conflict, finding differences in how each scaled to large numbers of contributors. Our results suggest that coordination mechanisms effective for managing conflict are not always the same as those effective for managing task quality, and that designers must take into account the social benefits of coordination mechanisms in addition to their production benefits.