Reciprocity Whenever human activities incorporate machines or rigidly prescribed procedures, the modes of human interaction change. In general, technical arrangements reduce or eliminate reciprocity. Reciprocity is some manner of interactive give and take, a genuine communication among interacting parties. Ursula M. Franklin, The Real World of Technology reciprocity
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