Ludovic Le Bigot

Mode and modal transfer effects on performance and discourse organization with an information retrieval dialogue system in natural language

This paper describes an experiment on the effects of learning, mode of interaction (written vs. spoken) and transfer mode on user performance and discourse organization during interaction with a natural language dialogue system. Forty-eight participants took part in a series of 12 dialogues with an information retrieval system presented either in the written or the spoken mode during the first six dialogues. The next six dialogues were then presented either in the same interaction mode or in another mode. The analysis of the results showed that performance (time, number of effective turns) improved throughout the dialogues whatever the mode of interaction. Nevertheless, performance was higher in the written mode. Moreover, mode-specific characteristics were observed. These consisted in greater use of subject pronouns and articles in the spoken mode. Similarly, in the spoken mode, the users found it easier to re-use the formulations presented in the system speech than in the written mode. Furthermore, the analysis also revealed a positive transfer effect on performance and discourse organization when the individuals first interacted in the spoken mode and then in the written mode. Both positive and negative transfer effects were observed when the individuals interacted first in the written mode followed by the spoken mode. The implications of the results are discussed in terms of direct and indirect consequences of modality effects on natural language dialogue interaction.

Asymétrie du transfert modal lors d'un dialogue personne-machine

The aim of this study was to explore modal transfer effect with the use of retrieval information system. Forty-eight participants took part in a series of twelve tasks with a dialogue system presented either in the written or the spoken mode during the first six dialogues. The next six dialogues were then presented either in the same interaction mode or in another mode. The analysis of the results showed a changing of interaction mode reduced efficiency. Moreover, beginning by oral mode had a positive effect on the next interactions with both oral and written modes. The implications of the results are briefly discussed depending modality effects on natural language dialogue interaction.

De la représentation de l'interlocuteur vers un modèle utilisateur formel pour le dialogue personne-machine

This paper proposes the formalization and implementation of user model. It is based on an interlocutors model in natural language dialogue system. Experimental studies on interlocutors representation and, particularly, on users familiarization with the system were used for the results analyses. The analysis of the results has shown the more the user is familiarized the more he gives relevant information for research in his first utterances, and with the same number of words. The formalization proposed concerns (1) users expertise or familiarization level, and (2) the detection of this level. The extended user model allows the system to adapt and thus, to contribute to increase usability and its efficiency in the information research processes.