Abstract. Mixed reality, as an approach in human-computer interaction, is often implicitly tied to particular implementation techniques (e.g., see-through device) and modalities (e.g., visual, graphical displays). In this paper we attempt to clarify the definition of mixed reality as a more abstract concept of combining the real and virtual worlds -that is, mixed reality is not a given technology but a concept that considers how the virtual and real worlds can be combined. Further, we use this discussion to posit robots as mixed-reality devices, and present a set of implications and questions for what this implies for mixed-reality interaction with robots.