Design for Usability

Noise Impairs Usability

Backgrounds

The default browser background is a light grey, reinforcing Edward Imhof's concept (outlined in Cartographic Relief Presentation) that spots of color against a light or grey background will both highlight data and also be easy on the viewer's eyes. Conversely, pure or very bright strong colors are loud and can be unbearable when spread across large areas with little relief.

"Noise is not music. Only a piano allows a crescendo and then a forte, and only on a quite background can a colorful theme be constructed," he writes.

Wired's subscriber base notwithstanding, readability studies in print media have consistently validated the theory that black backgrounds with "reverse type" (white or another light color) are more difficult to read than light backgrounds with dark type.

And at least on paper, neon colors don't flicker.

Thus, web site designers who are concerned about usability and readability should avoid busy background GIFs and black or almost black solid background colors, particularly if a page is text-intensive. Printing these pages is also a chore.

Web site examples:

• University of Florida Agricultural Site Index
  The designer uses a kelly green background for those who visit with graphics off; the lack of contrast with link colors makes this hard to read. Also, there is forced line widths and centered text and graphics.

• V Multidimensional Signal Processing
  Busy and black.