Marc Hassenzahl

Our interactions with technology do not just shape our individual experiences. They also affect people around us. Although previous research has addressed such "witness" experiences, the actual effect of interaction design on the witness experience remains largely unknown. In an online study (n = 407), we explored how witnesses perceive mid-air gesture-based interactions with a hearing aid, using four video vignettes. We studied witnesses' subjective visibility of manipulations and effects (following Reeves and colleagues' taxonomy), perceived form of interaction, subjective experience, and relationships between these measures. Although visibility patterns matched the intended form, they did not lead to the supposed experience (i.e., "suspenseful" gestures did not lead to suspenseful experiences). The paper illustrates gaps in current research about witness experiences, demonstrates the need to overcome basic hiding/revealing profiles, and indicates a path forward by focusing on aesthetic forms and experiences.