Trust Mediating Reliability–Reliance Relationship in Supervisory Control of Human–Swarm Interactions

Objective This work aims to further test the theory that trust mediates the interdependency between automation reliability and the rate of human reliance on automation. Background Human trust in automation has been the focus of many research studies. Theoretically, trust has been proposed to impact human reliance on automation by mediating the relationship between automation reliability and the rate of human reliance. Experimentally, however, the results are contradicting as some confirm the mediating role of trust, whereas others deny it. Hence, it is important to experimentally reinvestigate this role of trust and understand how the results should be interpreted in the light of existing theory. Method Thirty-two subjects supervised a swarm of unmanned aerial vehicles (UAVs) in foraging missions in which the swarm provided recommendations on whether or not to collect potential targets, based on the information sensed by the UAVs. By manipulating the reliability of the recommendations, we observed changes in participants’ trust and their behavioral responses. Results A within-subject mediation analysis revealed a significant mediation role of trust in the relationship between swarm reliability and reliance rate. High swarm reliability increased the rate of correct acceptances, but decreased the rate of correct rejections. No significant effect of reliability was found on response time. Conclusion Trust is not a mere by-product of the interaction; it possesses a predictive power to estimate the level of reliance on automation. Application The mediation role of trust confirms the significance of trust calibration in determining the appropriate level of reliance on swarm automation.