This paper presents the main results of a three-year long field and design study of proactive information technology in the home. This technology uses sensors to track human activities in order to proactively anticipate the direction of human activity. With it, it could be possible to build an environment without buttons and remote controls. However, the home represents a series of design challenges for proactive technology. This paper describes how we have identified suitable areas for proactive designs with user research, how we built several “minidesigns” and experience prototypes, and how we tested them in a series of five field studies in the Tampere and Helsinki regions in Finland. The paper ends with a section in which we outline some of the main design principles learned in these studies, and point directions for studies in the future. Author Keywords Proactive technology, ubiquitous computing, home, field study ACM Classification Keywords H5.m. Information interfaces and ...