III-COR-small: Harvesting Concept Hierarchies from Social Data

University Of Southern California, Los Angeles CA

Investigators

Abstract

The Social Web is changing the way people create and use information. Sites like Flickr, Del.icio.us, Digg, and others, enable users to publish and organize content and participate in communities. The information they create while interacting with content and other users is called social metadata. Tags, one example of social metadata, were introduced as a means for individuals to organize their content by assigning freely-chosen keywords to it. Some Social Web sites now also allow users to organize content hierarchically. The photosharing site Flickr, for example, allows users to group related photos in sets, and related sets in collections. Although social metadata lacks formal structure, it captures the collective knowledge of the community. Once extracted from the traces left by many users, such collective knowledge will add a rich semantic layer to the content of the Social Web. This project will develop a probabilistic framework to combine diverse types of social metadata to construct a common concept hierarchy. In addition, the methods developed by the project will use social relations, in the form of community participation, to discover community-specific vocabularies and concepts, and identify facets of multi-dimensional concepts. In the future, Social Web sites and data management tools will allow users to express ever richer types of knowledge, including complex predicates and semantic relations. The ability to aggregate individually expressed knowledge into a unified whole will transform the way people use information. Global concept hierarchies, for instance, can help users visualize how their content relates to that of others and allow for more efficient browsing, search and discovery. By linking content to a common concept hierarchy, the methods developed by the project could also be used to integrate disparate data and align it across domains. The proposed work, therefore, addresses one of the more important emerging questions in AI, namely, how to harness the power of collective intelligence. For further information about this project, please see the project Web site at http://www.isi.edu/~lerman/projects/folksonomy.html.