The skill of perception The newborn baby and the [blind man suddenly gifted with sight] do not have to learn to see. Sight is given to them. But they do have to learn to perceive. Perception is learnt and learnt slowly. Skill is required for perception as for speech. We are largely unaware of the skill we exercise. None of the things we have to learn to perceive are self-evident, or, apparently, instinctively evident. No doubt, however, we have an instinctive aptitude for this learning, and once we have learnt we cannot easily see as though we had not. As Ruskin says, one has to strive, if one is to see with the 'Innocent Eye'. David Pye, The Nature and Aesthetics of Design The innocence of the eyethe innocent i seeingperceptionlearninginstinct
Up and Down the Ladder of Abstraction An Essay by Bret Victor worrydream.com The most powerful way to gain insight into a system is by moving between levels of abstraction. Many designers do this instinctively. But it's easy to get stuck on the ground, experiencing concrete systems with no higher-level view. It's also easy to get stuck in the clouds, working entirely with abstract equations or aggregate statistics. This interactive essay presents the ladder of abstraction, a technique for thinking explicitly about these levels, so a designer can move among them consciously and confidently. From a roving viewpoint abstractionunderstandinginteraction