2.3 Principle 3 - Understandable

Under the principle of understandable [ http://www.w3.org/TR/2008/REC-WCAG20-20081211/#understandable ], the guidelines state that information and the operation of user interface must be understandable.

The W3C says:

  • Make text readable and understandable.
  • Make content appear and operate in predictable ways.
  • Help users avoid and correct mistakes.
From: WCAG 2 at a Glance [ http://www.w3.org/WAI/WCAG20/glance/ ]

To effectively communicate, we must realize that we are all different in the way we perceive the world and use this understanding as a guide to our communication with others.

— Tony Robbins

Don't make me think.

— Steve Krug, usability expert

There's an old story about the person who wished his computer were as easy to use as his telephone. That wish has come true, since I no longer know how to use my telephone.

— Bjarne Stroustrup