Typical Human Robot Interaction (HRI) assumes that the user explicitly interacts with robots. However, explicit control with robots can be unnecessary or even undesirable in certain cases, such as dealing with domestic services (or housework). In this paper, we propose an alternative strategy of interaction: the user implicitly controls a robot by issuing commands on corresponding real world objects and the environment. Robots then discover these commands and complete them in the background. We implemented a paper-tag-based interface to support such implicit robot control in a sensor-augmented home environment. Our initial user studies indicated that the paper-tag-based interface is particularly simple to use and provides users with flexibility in planning and controlling their housework tasks in a simulated home environment. Author Keywords Implicit Human Robot Interaction, Magic Cards, Paper-tagbased interface, Domestic service. ACM Classification Keywords H5.2. [Information interfa...