About User Interface Design Principles
to adapt your application's interface to the Apple Desktop Interface provided
with system 7.0. It describes new user interface guidelines and clarifies
existing guidelines. It also introduces several user interface topics that you
need to consider when you design or redesign an application. Throughout the
section are references to places where you can find more information about
technical implementation issues.
Your application should maintain the spirit of the Apple Desktop Interface and
remain consistent with the guidelines presented earlier here and in Inside Macintosh, Human Interface Notes, and Human Interface Guidelines: The Apple
Desktop Interface-which present a complete description of the Apple Desktop
Interface.
the Apple Desktop Interface. It's a brief reminder of the basic premises that
you should consider when you design your application for the Macintosh
computer.
• Metaphors from the real world. Concrete, simple metaphors
provide people with a set of expectations to apply to computer
environments. Whenever appropriate, audio and visual effects can
support the metaphors.
• Direct manipulation. Each user action has a perceptible response
and the Operating System provides feedback to verify the effect of the
action. For example, icons move when users drag them. In the
Macintosh interface, people do not have to trust that abstract commands
entered in a text-based interface do what they promise. This means that
when users choose the Bold command, a word changes immediately to
boldface- in comparison to other operating systems in which users
type in commands and wait to see the results when the document is
printed.
• See-and- point (not remember-and-type). Users rely on
recognition, not recall, so entities are visible when possible. People do
not have to remember anything the computer already knows, such as
which commands are available.
• Consistency. Effective applications are internally consistent and
consistent with other applications.
• WYSIWYG (what you see is what you get). There is no
significant difference between what users see on the screen and what
eventually is printed.
• User control. Users, not the computer or the application, initiate
and control all actions.
• Feedback and dialog. Users get feedback about all interactions with
the computer, and it is immediate feedback when possible. This
communication should be brief, direct, and expressed in the users'
vocabulary rather than the programmer's.
• Forgiveness. As users explore the interface, their actions should
generally be reversible so that people explore and learn by doing.
Users should be able to identify in advance any actions that are not
reversible.
• Perceived stability. Users feel comfortable in a computer
environment that remains understandable and familiar rather than one
that changes randomly.
• Aesthetic integrity. Visually confusing or unattractive displays
detract from the effectiveness of human- computer interactions.
Therefore different things, like folders and documents, should look
different on the screen. Also, users should be able to control the
superficial appearance of their computer workplaces to display their
own style and individuality. Messes are only acceptable if users make
them. Applications are not allowed this freedom.
For further explanation of these design principles, see Human Interface
Guidelines: The Apple Desktop Interface.