Designing the expressivity of multiple smart things for intuitive and unobtrusive interactions

Connected products and systems are becoming popular, but they seldom provide direct and intuitive communication to the users. In this study, we applied Disney's animation principles to design the expressivity with LED lights and speakers commonly embedded in electronic devices. We explored the subtle transitions of brightness and controlled the timing to compose individual and system-level behaviors with multiple devices. The designs were evaluated and improved through three iterations. In the main study, we recruited 16 designer participants to investigate whether lights and sounds could be intuitively interpreted as what the system wanted to convey. The result shows that group light behaviors could evoke meanings that are highly similar to the intents of the system. When the acoustic accompaniments were provided, participants could better perceive the presence of devices. We concluded with six sets of light behaviors that are capable of expressing smart devices and systems' intents intuitively and unobtrusively.