Directness

Design your interface so that users can directly manipulate buttons and representations of task information. Whether they are selecting an object to activate it or navigating to a location, users should see how their actions affect the objects on the panel. Visible information and choices also reduce the user’s mental workload. Users can recognize a command more easily than they can recall its syntax.

Familiar metaphors provide a direct and intuitive interface for user tasks. By allowing users to transfer their knowledge and experience, metaphors make it easier to predict and learn the behaviors of interface-based representations. When using metaphors, you need not limit a computer-based implementation to its real-world counterpart. For example, unlike its paper-based counterpart, a folder can be used to organize a variety of objects such as hardware, task functions, and other folders. The purpose of using metaphor in the interface is to provide a cognitive bridge; the metaphor is not an end in itself. Metaphors support user recognition rather than recollection. Users remember a meaning associated with a familiar object more easily than they remember the name of a particular command.