From the perspective of knowledge reusing and sharing, this paper proposes to employ ontology to support user modeling in the realization of interface agents. Ontology, its construction, and how it is used to support user modeling are presented. An example interface agent that employs the technique to support user modeling for information retrieval from Internet is illustrated. We conclude the work with the following interesting observations. 1) A better user model can be constructed if supported by domain-specific ontology. 2) Based on the structure of the ontology, we can generate proper dialogues in accord with the user proficiency levels to support user query processing. 3) An ontology-supported user model provides the underlying physical meanings for system operations. 4) Since ontology is domain-specific, it serves as a strong method to do user modeling, and makes the interface agent truly personal.

We are investigating computational models for humancomputer interaction based on a uniform, declarative, knowledge representation. We describe a new implementation of our work called Equuleus, a system for interactive, adaptive, document presentation. Equuleus achieves this by using annotated descriptions of a document to be presented and a planner to plan the document’s presentation. All presentation occurs as a result of planning and re-planning presentation goals.