How to improve human-robot interaction with Conversational Fillers

Conversation Fillers (CFs), such as `um', `hmm', and `ah', may help to improve the human-robot interaction by smoothening the robot's responses. This paper presents the design and test of such CFs - alongside iconic pensive or acknowledging gestures - for Wizard of Oz (WoZ) controlled open-ended dialogues in child-robot interactions. A controlled experiment with 26 children showed that these CFs can improve the perceived speediness, aliveness, humanness, and likability of the robot, without decreasing perceptions of intelligence, trustworthiness, or autonomy.