We describe the results of an experiment investigating whether an avatar’s facial feedback can enhance turn-taking, undertaken as part of a usability study of a preliminary version of the COMIC multimodal dialogue system. The study focused on the phase of the interaction where the avatar embodies a virtual sales agent that guides the user through a range of possible tiling options for his or her newly redesigned bathroom. Our experiment employed a between-subjects design, where subjects used the system in one of two face conditions: (1) the “expressive” condition, where lip sync, blinking, facial expressions, gaze shifting and head turning were enabled; or (2) the “zombie ” condition, where only lip sync was enabled. The results of the study were mixed, with some positive results on improving the interaction quality, but some unexpected negative results on task success and ease. On the positive side, the responses to our questionnaire indicated that the avatar’s thinking expression helped to convey that the system was busy processing input—confirming Edlund and Nordstrand’s (2002) finding—and that the facial expressions mitigated the system’s perceived sluggishness in responding verbally. However, after examining the videos of the interactions, we concluded that the avatar’s facial feedback—though helpful with some users—was unlikely to make up for the unnaturalness of the system’s half-duplex interaction on its own, and thus should be used together with explicit signals such as busy cursors. We did also find that the subjects in the expressive conditio
