An Agent System Reasoning about the Web and the User

The paper describes some innovations related to the ongoing work on the GSA prototype, an integrated information retrieval agent. In order to improve the original system effectiveness, we propose the GSA2 system, introducing a new internal architecture based on a message-passing framework and on an ontology description formalism (WOLF, Web ontology Framework). GSA 2 is conceived in order to describe and easily perform reasoning on "facts about the web and the user". The most innovative aspect of the project is its customizable and flexible reasoning system, based on Answer Set Programming; it plays the role of the central decision making module, and allows the Agent to take proactive decisions. The introduction of a logic language allows one to describe, program and plan behaviors of the Agent easily and quickly, and to experiment with a large variety of Information Retrieval strategies. Both the System Architecture and WOLF are general and reusable, and the result constitutes a good example of real implementation of agents based on logics.