Today, the interaction between human and computer (HCI) is an important design task for all services and products. But how can designers predict the quality perceived by the user when they plan and design a system from scratch? How can designers provide systems that will most likely satisfy user’s expectations? One approach is to understand the design process as rhetorical communication that has to address an audience in an appropriate way. It is an interdisciplinary approach from design research and humanities reflecting on the ancient technique of strategic communication that is applied to media communication. The rhetoric of HCI is a theory to explore the communicative interaction between system designer, the system itself, and the user. The aim of this paper is to elicit this transfer with a basic communication model that shows the dependencies and forces between these three parties: designer, system and user.