The problem of human-computer interface design was brought to the foreground with the emergence of the personal computer, the increasing complexity of electronic systems, and the need to accommodate the human operator in these systems. With each new technological generation discovering the interface design problems of its own technologies, initial emphasis has always been placed on the design of the surface features of the interface, with underlying principles emerging only after much study and experimentation. Consequently, much design work addresses surface values of final products without considering the underlying structural issues of the interface. Decomposing the interface design problem into multiple, interrelated design sub-problems allows designers to focus their decision-making with greater precision on smaller, more tractable problems, while promoting the coherence of the overall design. This article explores these issues as they emerged and were elaborated in a classroom design project that produced a prototype of a university mentor-finder Web page for students. Several important design concepts were illustrated by this experimental design project: (1) the value of using a functional architectural skeleton, (2) the value of specifying the minimum set of required functions, (3) the need for design representation tools that preserve the underlying logic of the architecture as the design changes, (4) the value of layer principles in page detail design, and (5) the unexpected logic that produced a surface-last design order.