The Human-Computer interface is crucial to good design support tools. It has to be non-interruptive and non-distracting, yet allow the architect to interact with the computer software. The physical reality of the interface, such as the shape and manipulability of devices like the mouse, keyboard, joystick, or data-glove, has to be mapped on actions and commands in the software. Already the current user interfaces are felt to be inadequate for a good support of design, and the functionality of design tools is growing, requiring even more and new physical interface devices. In this paper, we present research on new tangible interfaces for architectural design support. In particular, we focus on the research methodological question how to investigate such devices. The research strategy is introduced and discussed, after which concrete implementations of this strategy are shown. Based on this work, we conclude that the combination of interface and the context of its use in terms of design method and how the user is involved form crucial aspects for such research and cannot be considered separately.