Abstract. To investigate how participants in peer production systems allocate their time, we examine editing activity on Wikipedia, the well-known online encyclopedia. To analyze the huge edit histories of the site's administrators we introduce a visualization technique, the chromogram, that can display very long textual sequences through a simple color coding scheme. Using chromograms we describe a set of characteristic editing patterns. In addition to confirming known patterns, such reacting to vandalism events, we identify a distinct class of organized systematic activities. We discuss how both reactive and systematic strategies shed light on self-allocation of effort in Wikipedia, and how they may pertain to other peer-production systems.

We present a visualization system for reviewing the turn-taking patterns in a face-to-face meeting. Without the need to directly observe a group, a user can use the system to gain insight into the interaction dynamics of a meeting. We evaluated the visualizations by asking outside observers to make qualitative judgments about the individuals represented visually, and then compared their assessments to our own, made from direct observation of the meetings.Social psychologists suggest that one way a group can improve its interaction and consequently its productivity is by having a high-level understanding of its emotional and social interaction [4]. Furthermore, a group can gain insight into its interaction by viewing an aggregate report of its behavior [1]. We therefore postulate that an automated method for collecting