Game Development Reference
should foster an environment safe for exploration. Safe environments are achieved
through the use of undo and redo functionality. A great interface design invites
and rewards user exploration, and offers the thrill of discovery and the satisfaction
of unassisted accomplishment. Undo and redo functionality encourages your users
to explore the application without fear of corrupting the database or game content.
Another great design advantage of undo and redo functionality is that it eliminates
the need for dialogs requesting permission to perform an erroneous function. This
is also a great technique to enhance interface transparency.
Principle of Modality
The use of modal dialogs is quite common in a user interface, yet they must be
used wisely for a number of reasons. Programs generally use modal dialogs to
force users to perform steps in a specific order. Modal dialogs are very advanta-
geous for wizard tools that simplify complex tasks, and are also used to display
warning and error messages for a critical issue that the user must first address
before returning to the task.
The problem with modal dialogs is that they make users uncomfortable because
they restrict natural or intuitive responses. Modality also interrupts user concen-
tration and goal-oriented behavior, decreasing productivity with the tool.
Modal dialogs are a great way to build easy-to-use and straightforward interfaces,
but they have to be used sparingly. Task sequencing techniques can be applied so
that modal dialogs are only used when absolutely necessary.
Principle of Self-Evidence
Good applications have online reference materials and comprehensive manuals
that explain features of the application and help to solve real-world problems. If a
user is stuck on a particular problem, in theory he should be able to read the ref-
erence material, move past his issues, and resume productivity.
Great applications have online reference materials and comprehensive manuals
available to the user, but users rarely need to refer to them to figure out how to per-
form a particular task. This is where the concept of a self-evident application
comes into play.
A number of factors contribute to an interface that is self-evident; some of the
factors include consistency, feedback, modality, and an environment that is safe for