Empirical studies can help characterize media usage in Internet-based collaborative environments and how they support architectural design. The information gained can lead to development of better tools, improved business practices, innovative educational approaches, and more effective design instruction. A rigorous controlled experiment has revealed hard evidence of how people use a collaborative environment to support architectural design. Teams of students undertook a short architectural design problem using a commercially available collaboration support software package. We observed that users employed shared drawing channels and audio channels more than text-based channels or video channels. Participants worked concurrently to a greater extent than was expected. A shared whiteboard tool was particularly useful in design analysis and coordination, while shared CAD environments supported synthesis and evaluation.