Usability may be many things to many people, but the implications of usability affect everything we do! From Donald Norman's observations about the design of everyday things, to the most methodical usability engineering approach, our own personal experiences reign supreme in judging whether something works as it should.

Thus has evolved a body of knowledge and an assortment of technologies for evaluating personal experiences — interactions — with a host of devices, tools, software programs, Web sites, environments, buildings, appliances, machines, and equipment types. Radios, supermarkets, computer games, planes, traffic intersections, cameras, personal digital assistants, sidewalks, doorways, cars, parking lots, and tooth brushes are just some of the many routine candidates for rigorous ergonomic study!

Of the many applications for usability investigation, however, it seems that few have resulted in as much excitement and controversy in recent years as the study of software user interface design. In that context, usability is defined as the ease, speed, and pleasantness with which intended people can use a product. While the road to success may not be easy, the journey we collectively take to refine the software development process through usability principles will serve the software industry well.

Technical communicators in particular share a major stake in the advancement of software usability. To help support this objective, the STC's Usability Special Interest Group (SIG) offers numerous resources in the form of newsletters, toolkits, readings, and events at http://www.stcsig.org/usability/index.html.

In addition, the collection below represents a set of ideas and information that we plan to expand over time. Our chapter will continue to add to the material in the form of articles, editorials, demonstrations, FAQs, definitions, and resources. In the meantime, we welcome your ideas and comments!