Website Response Times An Article by Jakob Nielsen www.nngroup.com Users really care about speed in interaction design...A snappy user experience beats a glamorous one, for the simple reason that people engage more with a site when they can move freely and focus on the content instead of on their endless wait. 0.1 seconds gives the feeling of instantaneous response. This level of responsiveness is essential to support the feeling of direct manipulation. 1 second keeps the user's flow of thought seamless. 10 seconds keeps the user's attention. A 10-second delay will often make users leave a site immediately. uxperformanceinteraction
Wordless questioning The comparison of forms raises questions and drawing can be employed as a wordless questioning of form; the pencil seeks to extract from the complex whole some limited coherent pattern that our minds and eyes can grasp. The probing pencil is like the dissecting scalpel, seeking to expose relevant structures that may not be immediately obvious and are certainly hidden from the shadowy world of the camera lens. Jonathan Kingdon, In the Eye of the Beholder The World of the Sea