Professionals whose job it is to design user interfaces for computer software or test usability of software believe that successful design stems from both an understanding of users' work and the capabilities of technology. This text includes a large number of case studies of field research applied to the conception and design of computer products, each of which represent a different company's approach to a particular software design problem. In addition to the cases, appendices and chapters provide practical guidance, which include advice on interviewing methodology, templates for recording data and suggestions for data analysis.