It was pleasing to hear Tufte call his fifth principle the most important. "Good design is clear thinking made visible," he says. Throughout the day, Tufte constantly poked fun at the cartoon icons and rainbow effects in many of the examples, noting that these embellishments were there to obscure the fact that the images contained little content.
...."Only two industries refer to their customers as 'users'," he quipped, obviously disenchanted with his experiences with the computer industry and software interfaces. "The most common user activity of a web site is to flee as quickly as possible."
Good design is clear thinking made visible, bad design is stupidity made visible.
Jason Fried, "A little Tufte recap" Signal vs. Noise, 27 Aug 2004