CHAPTER 1
Newton and Its Users
1-4 Observe Basic Human Interface Principles
Make your application accessible to people around the world by including
support for worldwide capabilities in your designs from the beginning of
your development process. Take stock of the cultural and linguistic needs
and expectations of your target audiences.
Observe Basic Human Interface Principles 1
Effective software adheres to certain basic principles no matter whether it
runs on a Newton PDA, a personal computer, or a high-powered computer
workstation. These principles are based on the capabilities and processes not
of the machine but of the human operator—how people usually think, act,
and work.

Metaphors 1

Wherever possible, model the actions and objects in your program on
something from the real world. This trick especially helps inexperienced
users quickly grasp how your program works. Folders are a classic metaphor.
People file things in folders in the real world, so they immediately understand
the concept of filing data items in folders on a Newton. Other common
metaphors include scrubbing to delete data, tapping buttons to make things
happen, sending and receiving things through an in box and out box, setting
dates and times on calendars and digital clocks, and homing in on information
with alphabetic index tabs. Figure 1-1 illustrates some Newton metaphors.
Metaphors suggest a use for objects and actions in the Newton interface, but
that use doesn’t define or limit the implementation of the metaphor. For
example, a paper folder has a limited storage capacity, but a folder on a