The way a person interacts with a computer or electronic device. It comprises the screen menus and icons, keyboard shortcuts, command language and online help, as well as physical buttons, dials and levers. All input devices, such as a mouse, keyboard, touch screen, remote control, joy stick, game controller or data glove, are also included. In the future, natural language recognition and voice recognition will become standard components of the user interface.

The Bar Is Set Low
The user interface is the most important, yet least-understood area in the computer industry. Every application has only a handful of basic functions that users need all the time, yet they are often buried in arcane submenus that must be memorized. Worse yet, once bad examples are set by major vendors, others follow like sheep. Since popular applications are often hard to learn, users have come to expect that using software has to be difficult, when in fact, it could be downright simple if educated designers were involved.

Users Are Reluctant to Change
Because of the steep learning curves people have endured in the past, many are loathe to change applications. While the software industry constantly touts "productivity gains" for every new product, the lost hours figuring out how to do something, combined with the gun-shy reluctance to actually try a different product that might really be an improvement hardly enhance productivity. If we are to make computers more usable for the masses, the user interface and online documentation must be given much greater attention. See RTFM, naming fiascos, Freedman's law, Web rage and HCI.

It Can Change World History

Nothing could better highlight the importance of a user interface than the U.S. presidential election of 2000. The confusing punch card ballot used in Palm Beach County, Florida caused thousands of voters to vote for Buchanan rather than Gore or Bush, and the presidency hinged on the results. Is a ballot a user interface? You bet, because any designed interaction between man and machine is a user interface, and this one people will remember in the history books!