Ron Petrick's Webpages

Research talk

(Dialogue) Planning with Knowledge and Sensing, R. Petrick, slides from a talk presented at the Universität des Saarlandes, Saarbrücken, Germany, 2009-03-05.

[ slides ]


The problem of planning dialogue moves can be viewed as an instance of the more general AI problem of planning with incomplete information and sensing. While ordinary planning actions (such as those used by classical planners) typically change the state of the world, sensing actions change the knowledge state of the agent and often leave the world state unchanged. Sensing actions also complicate the planning process, since such actions require the ability to reason about an agent's knowledge state, and give rise to potentially infinite state spaces. Recent approaches from the knowledge representation and planning communities, however, have been effective at overcoming some of the representational and inferential drawbacks of sensing actions, and such actions have been applied in a variety of domains.

In this talk, I will give an overview of PKS (Planning with Knowledge and Sensing), a contingent planner that is able to construct plans with sensing actions and incomplete information. PKS works at the "knowledge level" by reasoning about how the planner's knowledge state, rather than the world state, changes as a result of action. PKS also supports features like functions, run-time variables, and simple program-like constructs as part of its action representation language. I will also report on work currently in progress that aims to use PKS directly as a platform for speech act-based dialogue planning.

This talk describes joint work with M. Steedman that builds on an approach first presented in [Steedman & Petrick 2007].