We work on methods for expressing and reasoning with user preferences, especially on multi-variate problems, where the set of possible choices will often be restricted by constraints. A major focus of our work has been on situations where the preference relation is only partially ordered. Preference reasoning includes both (1) comparative preferences formalisms that reason directly about an agent's preference relation, and (2) formalisms that compare alternatives by computing an overall degree of satisfaction for each alternative.
Comparative preference languages allow compact statements of preference over multi-variate problems. Our interests include:
In decision making problems, there is often more than one criterion (or objective) one wants to reason about. It can be hard to obtain precise tradeoffs between criteria, so this leads naturally to partially ordered preferences. In soft constraints formalisms, complete assigments are compared using the degree in which they satisfy a set of constraints. These degrees of overall satisfaction can be totally or only partially ordered. Areas of interest include the following: