Mixed-initiative, multi-source information assistants
While the information resources on the Web are vast, the sources are often hard to find, painful to use, and difficult to integrate. We have developed the Heracles framework for building Web-based information assistants. This framework provides the infrastructure to rapidly construct new appli- cations that extract information from multiple Web sources and interactively integrate the data using a dynamic, hier- archical constraint network. This paper describes the core technologies that comprise the framework, including infor- mation extraction, hierarchical template representation, and constraint propagation. In addition, we present an applica- tion of this framework, the Travel Assistant ,w hich is an interactive travel planning system. We also briefly describe our experience using the same framework to build a second application, the WorldInfo Assistant, which extracts and in- tegrates geographic-related data about countries thorughout the world. We believe these types of information assistants provide a significant step forward in fully exploiting the in- formation available on the Internet.