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.
modality transfer dialogue natural language learning spoken versus written