The effects of errors on system trust, self-confidence, and the allocation of control in route planning

The concept of trust is believed by some to compensate for feelings of uncertainty. Therefore, trust is considered to be crucial in people's decision to rely on a complex automated system to perform tasks for them. This experiment aimed to study the effects of errors on control allocation, and the mediating role of trust and self-confidence in the domain of route planning. Using a computer-based route planner, participants completed 10 route-planning trials in manual mode, and 10 in automatic mode, allowing participants to become equally experienced in operating both modes. During these so-called fixed trials, the numbers of errors in automatic as well as manual mode were systematically varied. Subsequently, participants completed six free trials, during which they were free to choose between modes. Our results showed that high automation error rates (AERs) decreased levels of system trust compared to low AERs. Conversely, high manual error rates (MERs) resulted in lower levels of self-confidence compared to low MERs, although to a lesser extent. Moreover, the difference between measures of trust and self-confidence proved to be highly predictive of the number of times automatic mode was selected during the six free trials. Additionally, results suggest a fundamental bias to trust one's own abilities over those of the system. Finally, evidence indicating a relationship between trust and self-confidence is discussed. (C) 2003 Elsevier Science Ltd. All rights reserved.