'Dr. Galvao has produced a well grounded methodology for making and managing design decisions.'' Tom MacTavish, Vice President Human Interaction Research, Motorola Labs Companies focusing on technical innovation are making products that place ever higher demands on users' abilities to understand and operate them. Innovation fails and resources are lost when products do not match user-interaction requirements. This book examines how to design user-product relationships into the core of a product's architecture, based on the information from product functions and user studies. Introduced is a Function-Task- Interaction methodology that identifies, represents and quantifies these relationships, and is supported by three case studies and an information system. The methodology presented is based on the concept of "affordances," and the first academic paper on it received the XEROX-ASME Best Paper Award at the 2005 Design Theory and Methodology Conference. This book is intended for professionals, researchers and students in the fields of design, engineering, architecture and marketing.