Collaborative curation in social production communities

The use of social production communities (SPCs) has become a common approach for building information repositories such as Wikipedia, Yahoo! Answers, and YouTube. In these systems, communities of users collaborate to produce a shared repository of information. We define collaborative curation as the tasks performed by these communities, and the processes, workflows, and policies that guide how users work together. This thesis seeks to study the implications of different curation processes, and the challenges that SPCs face in constructing information repositories. Our goal is to better understand the growth and evolution of SPC information repositories so that we can inform the design of SPCs. The first part of this thesis focuses on collaborative curation practices at a high level to learn about the design space of curation mechanisms and the impact that different mechanisms have on the evolution of SPCs. We begin with an analysis of Wikipedia's curation practices, studying how Wikipedia's editors decide which articles merit inclusion in the encyclopedia, and how the encyclopedia has grown over the years. We then conduct a user study using the MovieLens recommender system to compare two typical curation mechanisms—a wiki-like process, and a social voting process—in how they affect the growth of MovieLens' movie database. In the second part of this thesis, our focus shifts to challenges that SPCs face in collaborative curation. We start by looking at how skews in group composition can influence collaborative curation. SPCs typically rely on the efforts of self-formed and self-organized volunteer groups. Such groups may differ from the larger user community or from the general populace on multiple dimensions, including demographics, attitudes, and experience. We conduct two studies to study these differences in the context of Wikipedia. At the small-scale level, we examine how composition skews in small working groups can affect curation decision quality; at the large-scale level, we explore an apparent gender disparity amongst Wikipedia's community of editors. We close with an analysis of a type of malicious deviant behavior where users submit false data to an SPC in an attempt to manipulate choices made by fellow users.