Metaphors are important graphic tools that relate objects in cyberspace to objects that are familiar in the physical world such as desktops, file-folders, and trash-cans. Using a metaphor correctly will help users navigate by providing a sense of place, setting expectations about what is possible, and how to go about getting things done.

The right metaphor should help viewers understand what to do, be appropriate for the content, not have content that does not fit the metaphor, and is able to meet the expectations of the audience (Kristof & Satran, 1995).

The virtual objects used in the metaphor can be rendered as 2D, 3D, plain text; real images, synthetic ones or a combination. It is important that these objects have size, shape, orientation, weight, features, function and limitations that connect the experience with real-world objects and their limits. When the user views the object it needs to evoke the correct response (EDventure Holdings Inc., 1997). 

A navigational metaphor provides a familiar context that makes the search for information less abstract. An example would be an onscreen doctor's office where the user could click on instruments to get information about medical procedures.

A functional metaphor creates an environment where objects perform the functions they depict. The most familiar example is the desktop metaphor of most computer interfaces. Here folders are places to file documents, trash cans are places to throw things away and names and addresses can be found in an electric address book.

Navigational metaphors can be used in almost any information product. Functional metaphors are used more in software applications and high-end multimedia (Kristof & Satran, 1995). 

When you create your metaphor don't forget your user or audience by making intuitive and useful choices in your design.

Karla Bell