Usability Standard 8:
Keep the Design Simple

Dialogues should not contain information which is irrelevant or rarely needed. Every extra unit of information in a dialogue competes with the relevant units of information and diminishes their relative visibility.16

Busy graphics, intrusive multimedia presentations, many competing features, or too many navigational choices hinder the user. The design must be ruthlessly pared down to the most important elements, the most concise text, and a reasonable number of navigational choices (ideally five to seven but no more than nine).

One study finds that graphic design doesn't help users retrieve information from a site, and it may hinder them. "When users navigated, they often tried text links first, ignoring nearby graphics."17 The study does not address other functions of graphics, such as branding or general aesthetic appeal. But from a purely functional standpoint, the study shows graphics have little if any effect.

One frequent use of graphics is in creating a metaphorical site structure. Cooper defines the metaphor paradigm as the use of visual metaphors designed to help users make intuitive connections, such as using a scissors icon to represent "cut."

Using an extended metaphor to define the user interface is tempting but rarely successful:

"Metaphors offer a tiny boost in learnability to first-time users, but at a tremendous cost. By representing old technologies, most metaphors firmly nail our conceptual feet to the ground…. They have a host of other problems as well, including the simple facts that there aren't enough metaphors to go around, they don't scale well, and the ability of users to recognize them is questionable."18

The humor site Suck once adhered closely to an organizational metaphor of "a fish, a barrel, and a smoking gun." The fish was the day's new article, the barrel was the archive, and the smoking gun was, um, something. The fish survives as a regular cartoon character. The rest of the metaphor has been ditched. It wasn't flexible or descriptive enough.

Consider what Cooper calls an idiomatic paradigm. An idiom is created when a simple action or symbol is imbued with meaning. Scrollbars, dropdown menus, and radio buttons don't metaphorically represent anything. But after a few uses, everyone learns what they do and what they represent.

Branding takes advantage of idiomatic learning. Place the letters "i", "b", and "m" next to each other and they're a typo. They have no intrinsic meaning, nor are they a metaphor for something else. Place the letters together as part of a consistent logo and market the heck out of it, and people learn what IBM means. They don't ask why or how those letters signify something, they just learn the meaning. On a site, a few simple graphics used consistently will help users navigate more intuitively on every visit.