Proceedings of the 2nd Workshop on Adaptive Systems and User Modeling on the WWW
The 8th World-Wide Web Conference, Toronto, CA, May 11, 1998

Tracking Incremental Change of User Interests on the Web

Henry Lieberman
Aileen Tang
MIT Media Lab

Many projects involving user modeling treat the user's interests as a static target to be successively approximated by the system. But users' interests and user profiles do change over time, and little has been studied concerning the nature of those changes. We conjecture that systems that track change of user interests dynamically can lead to some interesting results.

We have observed some properties of change of user interests through an agent, Letizia, that tracks Web browsing behavior. For example, we have found user interests tend to be "chunky" -- users tend to remain interested in a set of related subjects for a while, then make abrupt transitions to another subject. It is useful for the agent to know when such transitions occur, so that "subprofiles" can be created that represent changes of interest. Patterns such as tenative explorations that do not result in material of interest and quick returns to previous material can be easily detected so they do not "fool" the user modeling process. Groups of interests may be clustered to achieve greater coherency in the user model, and disparate interests separated. Users may return to previous interests at some future time, and the role of the agent can be to maintain the long-term "persistance of interest". Users are often attracted to items that represent an unexpected conjunction of interests, and a role of the agent can be to detect opportunistically such conjunctions when they occur. We are also experimenting with providing real-time visualization of interest profiles as feedback to the user.


Autonomous Interface Agents, Proceedings of the ACM Conference on Computers and Human Interface, CHI-97, Atlanta, Georgia, March 1997

Let's Browse: A Collaborative Web Browsing Agent, Henry Lieberman, Neil Van Dyke, Adriana Vivacqua, ACM Conference on Intelligent User Interfaces, Los Angeles, January 1999.

Letizia: An Agent That Assists Web Browsing, Proceedings of the International Joint Conference on Artificial Intelligence, Montreal, August 1995.