Design technology simulates a variety of senses but on the other hand restricts them to audio and visual responses. What happens if technology can accommodate more senses in the creation process and how does it affect the way we approach design? This paper investigates the implication of tangible interfaces in design computing. The focal point is to assess the factors of perception and cooperative working by employing an Augmented Reality (AR) setup with tangible interfaces in a design studio. A concept of usability evaluation is discussed with the focus on core theories and resulting methodology.