Polite speech strategies and their impact on drivers’ trust in autonomous vehicles

• Published in: Computers in human behavior Vol. 127; p. 107015
• Main Authors: Lee, Jae-gil, Lee, Kwan Min
• Format: Journal Article
• Language: English
• Published: Elmsford Elsevier Ltd 01.02.2022; Elsevier Science Ltd
• Subjects: Autonomous vehicle; Autonomous vehicles; Between-subjects design; Human–machine communication; In vehicle; Linguistics; Politeness; Social perception; Speech; Speech interface; Trust; Trustworthiness; User experience; Vehicles; Speech interface; User experience; Politeness; Autonomous vehicle; Human–machine communication
• ISSN: 0747-5632; 1873-7692
• DOI: 10.1016/j.chb.2021.107015

This study proposes adopting linguistic politeness in vehicle speech interfaces, as active communication between drivers and vehicles will become an essential part of driving with advanced autonomous driving technologies. Two between-subjects experiments were conducted to test the influences of politeness strategies (i.e., asking help, giving a reason, expressing gratitude) on drivers' perceptions of the vehicles. The results indicate that drivers evaluate polite vehicles as more sociable and trustworthy, and they perceive polite instructions were more acceptable. The results also suggest that providing reasons for requests and expressing gratitude for drivers' cooperation can be an optimal linguistic strategy in vehicle speech interfaces. Moreover, this study identifies the layers of heuristics in the process of shaping trust in autonomous vehicles. Drivers can instantly recognize politeness in vehicle speech interfaces, and this politeness heuristic was found to increase drivers' perception of social presence, thereby heightening drivers’ trust in the autonomous vehicles. •This study proposes the use of linguistic politeness in vehicle speech interfaces.•Drivers evaluate polite vehicles as more trustworthy, and perceive the vehicle's instructions as more acceptable.•Providing reasons for requests and expressing gratitude for drivers' cooperation can be an optimal instruction strategy.•This study identifies the layers of heuristics in the process of shaping trust in autonomous vehicles.