This paper uses Actor Network Theory to examine two cases of device-mediated educational change, one involving a computer-assisted interactive video module that provided a half-hour of instruction for a university course, the other an assistive communication device that proved a supposedly retarded pre-school child to be intelligent. The paper explores how device construction instigated by middle-level organizational workers can ramify into organizational change, and extends Actor Network theory by augmenting some of its conceptual tools. I argue that the organizational change (...) processes initiated by work on the devices played out in non-linear ways across the decades-long careers of their makers, and that to understand them we not only have to look across such extended time frames, but must also consider how agency and identity positions emerge and shift over time through the mediation of devices. (shrink)