Stanford’s B.J. Fogg is redefining simplicity. Not in the marketing sense (The Widget 3000: Redefining Simplicity!); this is something useful. That simplicity equals good user experience is a common perception, and rather than challenge it he and his team are examining exactly what it means to be simple.

This comes at a terrific time. Products like the iPhone are popularizing usable, delightful experiences, and for many the takeaway message is make it spartan. Some point to the Google home page as the perfect user experience because it contains so little. But good design isn’t about simplicity (in the English sense); it’s about context. Fogg’s simplicity framework builds a new concept of simplicity that incorporates context and perception.

Simplicity is the “minimally satisfying solution at the lowest cost.”

It is a function of the user’s scarcest resource at the moment and thus depends on the person and the context. It involves the following factors:

• Time: How long will it take?
• Money: What will it cost?
• Physical Effort: How much must I expend?
• Brain Cycles: How much must I think?
• Social Deviance: How weird will it make me look?
• Novelty: How different is it from what I’m used to?

It may not be intended as a complete design framework, but it is surprisingly comprehensive. Some of my favorite principles fit right in (consistency with expectations, the least effective difference, and a clear visual hierarchy, for instance). It does not, however, include the traditional definition of simplicity anywhere. In other words, while a spartan UI will often be the outcome of applying this framework, it won’t be when the context demands otherwise.

Fogg’s framework does omit delight as a factor. A delightful experience can predispose the user to accepting greater complexity, increasing simplicity through aesthetics. That may mean it belongs in the framework; but it may also belong outside it as a modifier.

Will this framework revolutionize user experience design? Probably not. But it can help designers explain the complexities of simplicity to others, and gives us tool for framing our own decisions and trade-offs.

UIE’s Joshua Porter has a worthwhile article on simplicity, with a discussion of its relationship to purchasing decisions and links to additional opinion.