Beyond Failures: A Comparative Study of Two Different Trust Violations and Their Effect on Trust

As human-robot interaction (HRI) grows in importance both in practice and research, the emphasis often lies on close collaboration and the complex dynamics of humans and robots working together. This development necessitates a deep understanding of crucial aspects of that interaction. One of these aspects is trust. The dynamics of trust appear to be diverse, and several factors can have an impact. To deepen our understanding of the multiple facets that trust in HRI entails, this research investigates the effects of different types of trust violations on trust during a handover task. Contrary to previous works focusing primarily on robotic failures, however, this paper emphasizes trust violations that appear to represent more realistic cases for understanding trust violations. Therefore, we compare a violation that can be seen as a clear failure with one that can be seen as a deviation from what a user would expect from the robot. Moreover, we implemented these two violations on two types of robots, a technical robotic arm and a humanoid robot, and compared their effects on trust. The empirical study was conducted with 40 participants. The results of the study revealed that there are no significant differences regarding the violation’s impact on trust–neither did the comparison of the robot types yield any significant differences. Potential reasons for this, along with its implications, are discussed.