Editorial

Welcome to this year’s third issue of the ACM Transactions on Human-Robot Interaction. We are excited to bring you five outstanding articles on a wide range of topics that showcase the diversity of the field of HRI, from legal and normative concerns, to robot learning, and the design of multimodal behaviors for interactive robots. Sarathy, Arnold, and Scheutz open up the issue with a thought-provoking exploration of how existing legal notions of consent can be applied to everyday HRI scenarios and applications, such as concerns that may emerge when robotic vacuum cleaners or waiters approach a person or when robots seek to manipulate objects in people’s environments as they assist them. The next two articles present innovative approaches to robot learning. Doering et al. combine data-driven offline learning with curiosity-driven online learning from HRI with a robotic shopkeeper to allow for on-the-fly adaptation to individual users, which they show can improve user experiences of the interaction. Oguz et al. describe an ontology of human-human interaction scenarios for one-on-one collaborative interactions in close proximity, which they apply to the development of behavioral policies for interactive robots using imitation learning. The final two articles consider the design and analysis of multimodal interactive behaviors and cues for robots. Thibault et al. present a new analytical framework for studying multimodal HRI in the context of different timescales of human action, from a few milliseconds to weeks or decades, and ways to make connections between them in user evaluations of HRI. Karreman et al. investigate how to design multimodal interaction behavior for non-humanoid robots. Their online and field studies with a museum guide robot suggest that, for non-humanoid robots, designing behaviors based on robot-optimized capabilities can lead to improved user experience when compared to simply imitating behaviors gleaned from human-human interaction models. The articles in this issue open up a wide set of options for the development and evaluation of human-robot interaction from ethical, technical, and design perspectives. We hope that reading this issue will provide you with inspiration for your own future studies and also motivate you to submit your newest work for consideration for inclusion in next year’s ACM THRI. We look forward to hearing from you!