Some perspective

The user is the most important part of any application. In the past, improving the speed or increasing the capacity of application software has been a major focus of computer programmers. The idea of emphasizing the user interface of a computer system over its performance and capacity is a relatively recent innovation in computer history.

Historically, most users of computer systems were technical people who could tolerate the exacting requirements of expensive computer hardware and their "unfriendly" application designs. Complex commands had to be remembered and typed into a terminal in the proper sequence and thus required these early computers to have a professional staff in order to run them. This made sense because the computing hardware of that era was much more expensive than human labour. The user was there to serve the needs of these expensive machines.

The advent of microprocessors and the long-term trend to lower-priced computers has changed all that. Today's computer user is trying to get work done. The user probably does not know much about computers and may not even know how to type. The human-machine interface has been reversed, and now computers must serve the needs of the user.

The User's Needs

The user's needs are simple:

The user needs: predictability, intuitiveness, accessibility, consistency,feedback,adaptability,and simplicity.


The user's needs listed above really all combine into one: consistency. If your interface is consistent with the model, it becomes predictable; if it can be scanned easily, it provides feedback; if it provides feedback in a reasonable manner, the user always feels comfortable and can master increasing levels of complexity.

Consistency in a user interface allows the user to apply previously learned knowledge to each new application. The user will spend less time figuring out how to get work done, and can therefore be more productive. Learning a new application is much easier if it works just like one the user already understands.

The Amiga is a multitasking computer that allows the user to run more than one application at a time. This makes consistency even more important because the user can easily switch from one application to another. Consistency between applications allows the user to make this switch without having to make a "mental jump" between one way of working and another.

Following standards also makes new applications more familiar; thus the user will probably be less afraid of inadventently wiping out data or making other non-recoverable mistakes.

Once again: predictability, intuitiveness, accessibility, consistency, adaptability, andfeedback, simplicity.

Filling the Needs

A graphic user interface (GUI) is current the best method available for simplifying the user interface and meeting the needs of the user.

Amongst the first computers to use GUIs were the Xerox Star and Apple Lisa. Based on pioneering research performed at the Xerox Palo Alto Research Centre in the 1970s, these computers allow the user to issue commands with a mouse and pointer. Resources represented by graphic icons can be activated by pointing to them with the mouse, and actions can be performed through mouse- activated menus.

GUIs provide immediate feedback and scanning ability, so users can tell what their options are and don't have to memorize commands. They allow for enormous growth and adaptability of an application, because levels of functions and commands can be buried yet still be graphically accessible. In short, they provide a user interface that lets the user operate, without learning, the computer - in much the same way that the average driver doesn't need to be versed in internal combustion.

By utilitizing standardized tools and objects provided in the GUI, programmers are less likely to invent needlessly different ways of doing things. The interface becomes predictable and consistent.

The Amiga

The Commodore Amiga is a further refinement of this philosophy that puts the needs of the user foremost. Like many other systems, the Amiga has a GUI with a mouse, pointer, windows and menus which makes it easier for users - especially beginners.

But the Amiga also offers two other built-in interfaces: a text-oriented interface, the Shell, an an inter-process scripting language, ARexx.

Together, these three interfaces provide a powerful and flexible environment for both the novice and the expert. In fact a philosophy for the design of the Amiga user interface might be "Power to the User".