This book catalogs well-known solutions to common UI design problems, and expresses them as a collection of patterns. These solutions are drawn from desktop software, web sites, web applications, and even consumer electronics. For each pattern, the book describes why these interfaces work as well as what they do, sometimes digging deep into software history, sometimes referring to recent cognitive science research, and sometimes using visual design principles well-known to artists but rarely taught to technical folk. Each pattern contains concrete examples, recommendations, design alternatives, warnings, and occasionally notes on implementation issues. Readers are shown, not just told, how to go about using these techniques in their designs.