Secure, Comfortable or Functional: Exploring Domain-Sensitive Prompt Design for In-Car Voice Assistants

User Experience in Human-Computer Interaction is composed of a multitude of building blocks, one of which is how Voice Assistants (VAs) talk to their users. Linguistic considerations around syntax, grammar, and lexis have proven to influence users’ perception of VAs. Users have nuanced preferences regarding how they want their VAs to talk to them. Previous studies have found these preferences to differ between domains, but an exhaustive and methodical overview is still outstanding. By means of an A/B study spanning over domains as well as dialog types, this paper methodically closes this gap and explores the degree of domain-sensitivity across different types of dialogs in German. The results paint a mixed picture regarding the importance of domain-sensitivity. While some degree of domain-sensitivity was found for in-car prompts, it generally seems to play a rather minor role in users’ experience of VAs in the vehicle.