Should driving support agents be explicitly instructed?

-Video-based evaluation of acceptability focusing on politeness strategies-

Abstract

In this paper, we examine the acceptability of the politeness strategy in the speech of driving support agents. The main speech of existing driving support agents corresponds to the off-record strategy in politeness theory. However, off-record strategies were not compared with other politeness strategies in the evaluation experiments of driving support agents in the previous studies, and the difference in the effects between the strategies was not clear. Therefore, we conducted a video-based subjective evaluation experiment to compare the acceptability of the off-record strategy, the positive politeness strategy, and the negative politeness strategy. The results of the experiment showed that the negative politeness strategy was rated significantly higher than the off-record strategy in the items related to functionality among the evaluation indicators of acceptability. This result suggests that it is useful for an agent to provide explicit instructions to a user with linguistic consideration when providing driving assistance.