Morena Danieli

Dialogos: a robust system for human-machine spoken dialogue on the telephone

This paper presents Dialogos, a real-time system for human-machine spoken dialogue on the telephone in task-oriented domains. The system has been tested in a large trial with inexperienced users and it has proved robust enough to allow spontaneous interactions both to users which get good recognition performance and to the ones which get lower scores. The robust behavior of the system has been achieved by combining the use of specific language models during the recognition phase of analysis, the tolerance toward spontaneous speech phenomena, the activity of a robust parser, and the use of pragmatic-based dialogue knowledge. This integration of the different modules allows to deal with partial or total breakdowns of the different levels of analysis. We report the field trial data of the system and the evaluation results of the overall system and of the submodules.

A robust system for human-machine dialogue in telephony-based applications

This paper presents a real-time system for human-machine spoken dialogue on the telephone in task-oriented domains. The system has been tested in a large trial with inexperienced users and it has proved robust enough to allow spontaneous interactions even for people with poor recognition performance. The robust behaviour of the system has been achieved by combining the use of specific language models during the recognition phase of analysis, the tolerance toward spontaneous speech phenomena, the activity of a robust parser, and the use of pragmatic-based dialogue knowledge. This integration of the different modules allows the system to deal with partial or total breakdowns at other levels of analysis. We report the field trial data of the system with respect to speech recognition metrics of word accuracy and sentence understanding rate, time-to-completion, time-to-acquisition of crucial parameters, and degree of success of the interactions in providing the speakers with the information they required. The evaluation data show that most of the subjects were able to interact fruitfully with the system. These results suggest that the design choices made to achieve robust behaviour are a promising way to create usable spoken language telephone systems.

Field trials of the Italian ARISE train timetable system

Abstract This paper reports results from two field trials of the CSELT A rise spoken dialogue system in the Italian railway call centre FS-Informa. The system provides voice-driven access to railway timetable for the major Italian and some European cities. On the basis of the initial experiences we have been able to integrate the automatic system in the architecture of a typical railway call centre, where preferable timetable information is interchanged with a caller via a spoken dialogue system, and where a human operator is involved only for answering more complex user requests. We argue that the results we present are relevant from different points of view. They allowed us to test the impact of the automatic system on the working routines of the human operators, and the reactions of real callers who are traditionally served by human operators.

Dialogue strategies for improving the usability of telephone human-machine communication

Interactions with spoken language systems may present breakdowns that are due to errors in the acoustic decoding of user utterances. Some of these errors have important consequences in reducing the naturalness of human-machine dialogues. In this paper we identify some typologies of recognition errors that cannot be recovered during the syntactico-semantic analysis, but that may be effectively approached at the dialogue level. We will describe how non-understanding and the effects of misrecognition are dealt with by Dialogos, a realtime spoken dialogue system that allows users to access a database of railway information by telephone. We will discuss the importance of supporting confirmation turns, and clarification and correction sub-dialogues. We will show the positive effects of robust dialogue management and dialogue state dependent language modeling, by taking into account both the recognition and understanding performance, and the success rate of dialogue transactions.

Integrating semantics and flexible syntax by exploiting isomorphism between grammatical and semantical relations

This work concerns integration between syntax and semantics. Syntactic and semantic activities rely on separate bodies of knowledges. Integration is obtained by exploiting the isomorphism between grammatical relations (among immediate constituents) and conceptual relations, thanks to a limited set of formal mapping rules. Syntactic analysis does not construct all the explicit parse trees but just a graph that represents all the plausible grammatical relations among immediate constituents. Such graph gives the semantic interpreter, based on Conceptual Graphs formalism, the discriminative power required to establish conceptual relations.

ADAM- An Architecture for xml-based Dialogue Annotation on Multiple levels

In this paper annotation modularity and use of annotation meta-schemes are identified as basic requirements for achieving actual corpora reusability. We discuss these concepts and the way they are implemented in the architectural framework of the ADAM corpus, which is a corpus of 450 Italian spontaneous dialogues. The design of ADAM architecture is compatible with as many practices of dialogue annotation as possible, as well as approaches to annotation at different levels.