Interface: Brenda Laurel defines interface as a contact surface: "It reflects the physical properties of the interactors, the functions to be performed, and the balance of power and control." In computer terms, this can refer to the visible toolbars and menus of a software program or the underlying operating system itself. Eric Gould expands on Laurel's idea by pointing out that interface "encompasses the place where the person and the system meet. It's the point of contact, the boundary and the bridge between the context and the reader."

I have some information on my web site that specifically discusses design. Please read over the following: http://www.cwrl.utexas.edu/~tonya/kairos/design/frames/
http://www.cwrl.utexas.edu/~tonya/Tonya/more/guidelines.html (off our links page)

Both links are geared toward design guidelines for the WWW, but the principles are sound in any authoring environment.

What follows are some suggestions or guidelines for interface construction:

• Content counts. The content is always more important that its packaging, but if the interface is unclear (or non-transparent), readers can't get to the information. Organize the content carefully‹it's the core of the project. The interface should serve the content, not vice-versa.

• Limit variation in typography to a few sizes from one or two font families. Just because you have access to three CD-ROMs full of fonts, don't go hog wild with their use. When writing in the text window in Director, you MUST choose a common font people will have on their computer systems. I recommend Palatino, Times or Helvetica. When creating a graphic image, the font you choose does not matter because it is translated into a visual image of text. In the end, it's readability that matters.

• Determine the structure and navigation for the project in advance. Develop a "map" for the overall structure, and come up with some simple navigational tools (<>)to orient the reader of the project.

• Make sure navigational tools like buttons and links give feedback (by depressing or highlighting the color) to the reader. Donald A. Norman points out that principles of good design can be summarized as four basic principles: visibility; a good conceptual model; good mappings; and feedback. Good visibility means a participant can look at a "device" and see the alternative possibilities for action. A good conceptual model refers to consistency in presentation of operations and "a coherent, consistent system image," i.e., the model makes sense. If you can easily determine the relationship between action and results and control and effects, the design has a good mapping system. The final hallmark of good design, according to Norman, relies on receiving feedback about your actions.

• To improve the quality of your images, select the right vehicle (elegant and distinctive), refine its cohesiveness (how does it relate rhetorically to the rest of the presentation?) and coordinate with the other groups to insure visual consistency.

Sources:

Gould, Eric Justin. "Empowering the Audience: The Interface as a Communications Medium." Interactivity. Sept./Oct. 1995: 86-88.
Laurel, Brenda, ed. The Art of Human-Computer Interface Design. Reading, MA: Addison-Wesley Publishing Co, 1990.
Mullet, Kevin and Sano, Darrell. Designing Visual Interfaces. NJ: Sunsoft Press, 1995.
Norman, Donald A. The Design of Everyday Things. New York: Doubleday, 1990, c1988.