The past decade has seen the development of a large number of spoken dialogue systems around the world, both as research prototypes and commercial applications. These systems allow users to interact with a machine to retrieve information, conduct transactions, or perform other problem-solving tasks. In this paper we discuss some of the design issues which confront developers of spoken dialogue systems, provide some examples of research being undertaken in this area, and describe some of the ongoing challenges facing current spoken language technology.

In this work we report our efforts to facilitate the creation of mixed-initiative conversational interfaces for novice and experienced developers of human language technology. Our focus has been on a framework that allows developers to easily specify the basic concepts of their applications, and rapidly prototype conversational interfaces for a variety of configurations. In this paper we describe the current knowledge representation, the compilation processes for speech understanding, generation, and dialogue turn management, as well as the user interfaces created for novice users and more experienced developers. Finally, we report our experiences with several user groups in which developers used this framework to prototype a variety of conversational interfaces.

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Abstract. We present the results of a study in which we contrast alternative forms of collaborative learning support in the midst of a collaborative design task in which students negotiate between increasing power and increasing environmental friendliness. Our research question is whether interactive instructional support in collaborative learning environments is more effective when it is offered as solicited or unsolicited help. The finding from our classroom study is that dialogue-based support is more effective in this collaborative context when invitations for help in the form of pointer hints are offered automatically, but dialogue agents are only provided when the invitation is explicitly accepted.

In this paper we summarize our experience at LIMSI in the design, development and evaluation of spoken language dialog systems for information retrieval tasks. This work has been for the most part carried out in the context of several European and international projects. Evaluation plays an integral role in the development of spoken language dialog systems. While there are commonly used measures and methodologies for evaluating speech recognizers, the evaluation of spoken dialog systems is considerably more complicated due to the interactive nature and the human perception of performance. It is therefore important to assess not only the individual system components, but the overall system performance using objective and subjective measures. 1. INTRODUCTION In our view, spokenlanguagesystems should provide a natural, user-friendly interface with the computer, allowing easy access to the stored information. At LIMSI we have experience in developing several spoken language dialog system...

As computers become more and more common in our everyday lives, a need is felt for moving away from the arcane interfaces in use today, to interfaces which are more intuitive and easier to use for the non-professional computer user. The most important such interfaces are speech and natural-language: communication media that all humans understand, and as of now, computers do not. This situation is rapidly changing, with the emergence of cheap and powerful speech-recognition and natural language parsing capabilities. This project aims to develop an airline reservation system (SEARS) which the user can interact with using plain English. The system tries to emulate a real airline reservation clerk's responses as faithfully as possible. A secondary aim of the project, integration with a commercial speech recognition tool, has not been met due to a variety of reasons. This report presents a description of the SEARS system, explaining the principles behind and design of each of it's components.

This article provides a global overview of the main aspects of current practice in the design, implementation and evaluation of speech recognition components for Spoken Language Dialog Systems (SLDSs) and presents the results of the DISC European project related to speech recognition. DISC and its successor DISC-2 are efforts towards the definition of best practice guidelines for SLDS development and evaluation. SLDSs aim at using natural spoken input for performing an information processing task such as automated standards, call routing or travel planning and reservations. The main functionality of an SLDS are speech recognition, natural language understanding, dialog management, database access and interpretation, response generation and speech synthesis. Speech recognition, which transforms the acoustic signal into a string of words, is a key technology in any SLDS.