PED: A Planner for Efficient Dialogues

Bryan McEleney

PED is a dialogue management system that uses a probabilistic nested belief model to choose dialogue strategies from a Bayesian game tree. The system designer is only required to supply a context-free dialogue grammar with preconditions. Using this grammar, PED constructs game trees (like the one below) to represent the outcomes of the dialogue. PED uses a belief revision function that makes inferences from the acts observed in the dialogue to update the belief model. PED is more efficient than other systems because it uses a probabilistic belief model. However, the belief revision function described here is approximate and I have not yet seen its solution. PED was developed as my PhD work at University College Dublin and was funded by the Irish government.



To browse my thesis on the web, try here. To download the PDF version, try here.

For something shorter, try one of these papers:

Bryan McEleney, Gregory O'Hare
Decision Theoretic Planning for Initiative Problems
Proceedings 10th International Conference on User Modelling 2005
July 23rd-29th 2005, Edinburgh, Scotland.

Bryan McEleney, Gregory O'Hare
Efficient Dialogue Using a Probabilistic Nested User Model
Proceedings of the Fourth IJCAI workshop on Knowledge and Reasoning in Practical Dialogue Systems
August 1st 2005, Edinburgh, Scotland.


To download a package with the PED source code, experiment scripts and experiment results, click here. The SWI Prolog interpreter using GNU/Linux is the recommended environment for running PED.

Bryan McEleney, December 2006.