Document Co-Organization in an Online Knowledge Community

We introduce the concept of "document co-organization" and describe such a system. By document co-organization we mean that individuals are allowed to hierarchically organize documents personally and share their hierarchies with others, while the system generates a "consensus" hierarchy from these personal hierarchies, which provides a full, common, and emergent view of all documents. By allowing users to retrieve documents from their own organization (hierarchy), another user's, the consensus hierarchy, or a time-based hierarchy, we provide access corresponding to different characteristics of knowledge tasks: they are personal, collective, social, and time-sensitive. In a class website experiment, we show that for a complex knowledge task, hierarchies are used more frequently than search. One surprising finding is how often students use others' personal hierarchies.