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
The minimum condition When a device is so designed that its component parts are only just strong enough to get the intended result without danger of failure, we may say it is in its minimum condition. I suspect that the functionalists sometimes meant by functional design simply design aimed at the minimum condition for a device. In that case 'form should follow function' would mean that every system should be in its minimum condition, thus having certain limitations imposed on its form. David Pye, The Nature and Aesthetics of Design Form follows function functionconstraintsdesignminimalism