GALAXY-II: a reference architecture for conversational system development

GALAXY is a client-server architecture for accessing on-line information using spoken dialogue that we introduced at ICSLP94. It has served as the testbed for developing human language technologies for our group for several years. Recently, we have initiated a significant redesign of the GALAXY architecture to make it easier for many researchers to develop their own applications, using either exclusively their own servers or intermixing them with servers developed by others. This redesign was done in part due to the fact that GALAXY has been designated as the first reference architecture for the new DARPA Communicator Program. The purpose of this paper is to document the changes to GALAXY that led to this first reference architecture, which makes use of a scripting language for flow control to provide flexible interaction among the servers, and a set of libraries to support rapid prototyping of new servers. We describe the new reference architecture in some detail, and report on the current status of its development.