The Need for Verbal Robot Explanations and How People Would Like a Robot to Explain Itself

Although non-verbal cues such as arm movement and eye gaze can convey robot intention, they alone may not provide enough information for a human to fully understand a robot’s behavior. To better understand how to convey robot intention, we conducted an experiment ( N = 366 ) investigating the need for robots to explain , and the content and properties of a desired explanation such as timing , engagement importance , similarity to human explanations, and summarization . Participants watched a video where the robot was commanded to hand an almost-reachable cup and one of six reactions intended to show the unreachability : doing nothing (No Cue), turning its head to the cup (Look), or turning its head to the cup with the addition of repeated arm movement pointed towards the cup (Look & Point), and each of these with or without a Headshake. The results indicated that participants agreed robot behavior should be explained across all conditions, in situ , in a similar manner as what human explain, and provide concise summaries and respond to only a few follow-up questions by participants. Additionally, we replicated the study again with N = 366 participants after a 15-month span and all major conclusions still held.