I recently had the opportunity to speak at BayCHI, where I gave a comprehensive review of the mission, philosophy, and specific heuristics that have guided Firefox's visual and interactive design through versions 3 and 4. This presentation was given at PARC on the eve of Firefox 4's launch.

I opened with a discussion of net neutrality, the underlying ideological roots of the PC industry, and Mozilla's mission to protect the Web. If you aren't that in to Internet freedom (really?), skip on ahead to time marker 9:35 where I describe two conflicting philosophies of UX design, and where Mozilla lands on that spectrum.

At time marker 19:20, I dive into the specific usability principles that have driven Firefox's design. These principles include:

  • external consistency
  • protecting cognitive flow
  • designing an iconic form
  • visual hierarchy
  • landmarks
  • efficiency of use
  • selective visual variables
  • creating a visually consistent conceptual model
  • leveraging spatial memory
  • utilizing usage metrics to streamline and refactor a UI