The Elements of Interface Design

Interface design encompasses three distinct, but related constructs--usability, visualization, and functionality (Vertelney, Arent, & Lieberman, 1990). Recently, a fourth component of interface design has emerged as a critical factor--accessibility. Interface design is most often associated with the development of Web pages, computer software, and multimedia, but is relevant to the creation of any instructional media or technical equipment.

I. Usability
refers to how intuitively or easily your media item is navigated and processed (flow, sequence, instructions, download time). Note, this construct is the most inclusive of the three and is influenced by both visualization and functionality.

II. Visualization
is creating visually interesting and aesthetically pleasing media items while avoiding potentially distracting or unncessary "bells and whistles."

III. Functionality
refers to the features of your media item and how useful they are for supporting a given task (e.g., interactive simulations, drill and practice quizzes, site maps, frequently asked questions, search engines).

IV. Accessibility
is an emerging Web interface design topic; if not addressed, it will negatively influence Web site usability for users with certain disabilities; tools that help users access your site in alternative formats (e.g., text, aural, visual) provide for increased functionality

Other Interface Design Links and Style Guides
(the theories and rules)

Publications and Organizations Showcasing Interface Design Samples for You to Emulate (the samples)