From tools to accomplish speci c narrowly de ned computational tasks, computers have morphed into assistants with whom we communicate almost continuously about a wide range of daily tasks. This has been paired with sophisticated software and ever-greater use of computer-controlled devices, from electronic communications to robotic assembly and computer-numericallycontrolled (CNC) fabrication devices. In this transformation, the “Run” command has been replaced by a complex interactive relationship with multiple virtual tools that demand, consume, and direct attention, mediate interpersonal relationships,

and permit us to edit or control complex data sets and processes anywhere on the planet with the result that computers form an integral part of systems for air-tra ccontrol, manufacturing, subway systems, and buildings. We are increasingly aware of the importance, limitations, and a ordances of the input and output mechanisms that constitute our interface with the machine, leading Paul Dourish, a prominent researcher from Xerox’s famed Palo Alto Research Center (PARC), to title his book on the subject Where the Action Is (2001).