International Journal of Actor-Network Theory and Technological Innovation, 3(3), 21-34, July-September 2011 21 Copyright © 2011, IGI Global. Copying or distributing in print or electronic forms without written permission of IGI Global is prohibited. Keywords: Activity Theory, Actor-Network Theory, Cultural Means, Innovation Evolution, Mediation, Tools, Translation INTRODUCTION The coexistence of humans and nonhumans characterises our lives. We are immersed in a world made of both social and technical arti- facts (Callon, 1986; Latour, 1986). The social world cannot subsist without technical artifacts as much as the latter only exists because of the former (Miettinen, 1999). These parallel asser- tions come from two realms concerned with the Mediated Action and Network of Actors: From Ladders, Stairs and Lifts to Escalators (and Travelators) Antonio Díaz Andrade, Auckland University of Technology, New Zealand, and Universidad ESAN, Peru Samuel Ekundayo, Auckland University of Technology, New Zealand ABSTRACT Both actor-network theory and activity theory call attention to the coexistence of people and technology. Although both theories provide analytical tools to understand the nature of the reciprocal action-shaping of humans and nonhumans, each puts emphasis on different conceptual elements of human activity. In this paper, the authors examine both activity theory and actor-network theory and present their similarities and differences, limitations, and complementarities. Using the theoretical lenses of both theories, the authors trace the evolution of an ordinary artifact to illustrate how researchers on the sociology of technology and innovations can beneft from these parallel theoretical approaches. study of the interplay between subjects and ob- jects: actor-network theory and activity theory. In this paper, we analyse these two – at the same time, similar yet contrasting – approaches. On the one hand, the focus of actor-network theory is on the dynamic and simultaneous interaction of both the social and the techni- cal assuming symmetry between human and nonhuman actors (Callon, 1986; Latour, 1986, 1999a, 1999b, 2005). On the other hand, the dialectic nature of cultural-historical activity theory postulates that human activity is always a materially and socially mediated object-oriented practice, whereby the object of activity is con- DOI: 10.4018/jantti.2011070102