Poly: Shape-changing Conversational Agent Helps Identify Multiple Characters in Storytelling

Abstract

In recent years, storytelling has attracted attention as a possible important application context for CAs. However, it is difficult to follow and recall the story flow by distinguishing their lines since most story content features multiple characters. We introduce Poly, a physically actuatable CA that implements a 2.5D shape display to help identify multiple characters in a story. To evaluate the effect of adding a novel approach of physical actuation into the conventional color expression technique, we conducted a 2×2 within-subject user study with two levels of shape change (shifting shapes by characters or not) and two levels of color change (shifting colors by characters or not) in a studio setting. The quantitative and qualitative analysis results show that shape change has a significant and exclusive effect on both user acceptance of Poly and narrative engagement of the story, although there is no interaction effect according to color change and shape change.