This article provides an overview of a research program developed over the past 20 years to explore relations between everyday practices and technology design and use. The studies highlighted reflect three interrelated lines of inquiry: (a) critical analyses of technical discourses and practices, (b) ethnographies of work and technologies-in-use, and (c) design interventions. Starting from the premise that technologies can be assessed only in their relations to the sites of their production and use, the authors reconstruct technologies as social practice. A central problem for the design of artifacts then becomes their relation to the environments of their intended use. Through ethnographies of the social world, the analyses focus on just how social/material specificities are assembled together to comprise our everyday experience.