Formalising control in robust spoken dialogue systems

The spoken language interface is now becoming an increasingly serious research topic with application to a wide range of highly engineered systems. Such systems not only include innocuous human-computer interactions, but also encompass shared-control safety critical devices such as automotive vehicles and robotic systems. Spoken Dialogue Systems (SDS) are the language architecture used to provide linguistic interaction in these applications, but they have to date been notoriously difficult to engineer in a robust and safe manner. In this paper we report on our efforts to improve the safety and overall usability of dialogue enabled applications through the employment of formal methods in SDS development and testing. Specifically, we use Communicating Sequential Processes (CSP) as the basis of a new approach to the specification, design and verification of dialogue manager control. Moreover to support this approach, we introduce FDMSC - the Formal Dialogue Management for Shared Control toolkit - and illustrate its use in the construction of formal methods based spoken dialogue systems.