Human–Computer Interaction

Computer Applications in Everyday Life

Computers are everywhere. We find the computer in life-critical systems such as traffic light control systems or the airport control tower. Many of the medical systems, imaging, diagnostic, and treatment, are computer driven. And at any workplace, be it the office or the factory, we find computerized systems: from word processing and accounting, through architectural or printed circuit board (PCB) design or newspaper typesetting, up to computer numerical control (CNC) machine control and material conveyance. Even at home we have computer games and Internet browsing. Our wristwatch, cellular phone, and personal digital assistants (PDAs) all are computers. Our interaction with computers has become a fact of life.

Interaction is Achieved via the User Interface

The user interface is the medium between the user and the computer that enables the interaction between them. The user interface consists of three basic components:

• 1.
  Controls: The controls are usually objects that enable giving commands to the system. These could [Page 323]be buttons, knobs, menus, sliders, voice commands, keyboards, and many more.
• 2.
  Displays: The displays are both the information conveyed to the user as part of the interaction and also the medium that conveys the information. These could be screens and monitors, sound, graphs and visualizations, text and narrative, printouts, and much more.
• 3.
  Interactions or Dialogs: The combination of giving commands and instructions to the computer, on one hand, and displaying information by the computer, on the other hand, merges together to become the dialog between the user and the computer.

Historical Perspective: From Character-Based to Graphical User Interface

In the beginning interaction with computers was achieved by using mediums such as punched card readers and magnetic tapes. Computing and processing were executed behind the scenes (batch work fashion) and the output to the user was printed. In other words, there was no direct communication or dialog between the user and the computer.

The concept of interaction appeared early in the 1960s. This concept referred to the dialog between human and computer, similar to human-to-human dialog. Interaction required technological progress such as the ability of the computer to speak with a number of users simultaneously (time sharing) and perform the processing for them during the interaction (realtime processing). There was also a need to develop the interaction channels and replace the punched cards and the printed output with something else.

Indeed, several technological developments in the computer world brought us closer to an interactive user interface. These developments included visual display units such as a cathode ray tube (CRT). The development of the displays started with presenting only characters to fully graphic displays showing pictures, drawings, and a variety of colors. The computer's processing units were developed in a way that enabled time sharing and real-time processing. The interaction channels included the appearance of the first mouse in 1965, use of a light pen that points on the screen, and a transfer to the digitizing tablet. In the 1970s many technological developments occurred that made a huge step toward the user interface as we know it today. These developments included the first personal computer by Xerox; and later Apple appeared and in 1977 presented its first personal computer.

...