This information can feed back into the design process as improved task descriptions for the next revision and better understanding on the part of the designer. In today's computer market there are few if any software products that can maintain their sales without regular upgrades. No matter how well the product is initially designed to fit its task and users, it will probably be inadequate in a few years. Tasks and users both change. Work patterns change because of the product itself, as well as because of other new hardware and software products.
Users gain new skills and new expectations.
Designers need to stay abreast of these changes, not only by watching the workplace in which their products are installed, but also by watching for developments in other parts of society, such as other work situations, homes, and the entertainment industry. The next revision of the design should be a response not only to problems but also to opportunities. If sending U.S. dollars is difficult, for example if you aren't in the U.S., send us something else you think we'd like to have. Or send us two somethings, one for each of us. No part of the book may be sold or included as part of a package for sale without the authors' written permission.