Since the early days of the Internet, people have gathered online to share knowledge and expertise as well as to socialize. Early systems for distributed conversations, like message boards or the Usenet, offered a minimalist text-based conversation. While these systems were notoriously plagued by poor signal to noise ratios, they also cultivated communities where people could find answers and experts thrived [8], [18]. Early interfaces offered grouped threaded messages but lacked features typical to current web forums such as personal profiles, reputation scores, and avatar images. Recently (since late 2005) purpose-built systems like Yahoo! Answers and Live QnA [1], [10] have been created explicitly as communities that offer expertise, as the “collective brain” and as “searchable databases of everything that everyone knows” [18].