When Automation Fails: Examining the Effect of a Verbal Recovery Strategy on User Experience in Automated Driving

Automated agents' errors will cause various negative influences on humans and their relationships with humans (e.g., reducing user experience). They are increasingly required to have social recovery strategies (e.g., human-like apology and explanation) to mitigate the negative impacts of their errors and maintain resilient human-automation relationships. However, the efficacy of these strategies in human-automation interaction (HAI) largely remains unknown, especially in less controlled environments. Here we conducted a test track experiment and designed a verbal recovery design (consisting of an apology, explanation, and promise) by an automated driving system (ADS) installed in a real automated vehicle after an ADS failure. We utilized a Wizard of Oz design to simulate the ADS' failure and its verbal recovery attempt (through a voice by a human or Apple Siri). Participants (N = 389) were assigned to four groups: normal (without experiencing the ADS failure), fault (experiencing the ADS failure), Siri-voice-recovery, and human-voice-recovery. The major measures were positive experience and negative experience while riding in the automated vehicle and perceived ADS usability. Overall, we found that the human-voice-recovery can to some degree mitigate the negative impacts of the ADS failure on user experience. The Siri-voice-recovery worked on positive experience but cannot restore it to that in the normal group. It implies that more empirical efforts are needed to examine social recovery strategies in HAI in natural environments, develop strategies specific to HAI, and offer effective guidelines for social recovery design.