Malcolm McCullough’s book “Digital Ground” (2004) has been the response of an architect to the design challenge posed by pervasive computing. It looks at how interaction design reflects not only how people deal with machine interfaces but also how people deal with each other in situations where interactivity has become ambient. McCullough offers an account of the intersections of architecture and interaction design, arguing that the ubiquitous technology does not remove the human need for place. His concept of “digital ground” expresses an alternative to anytime-anyplace sameness in computing; he shows that context not only shapes usability but ideally becomes the subject matter of interaction design and that “environmental knowing” is a process that technology may serve and not erode.