The application of activity theory to information systems derives from the work of Bonnie Nardi and Kari Kuutti.

Nardi's approach is, briefly, as follows:

  • Nardi saw activity theory as a "powerful and clarifying descriptive tool rather than a strongly predictive theory.
  • The object of activity theory is to understand the unity of consciousness and activity.
  • Activity theorists argue that consciousness is not a set of discrete disembodied cognitive acts (decision making, classification, remembering), and certainly it is not the brain; rather, consciousness is located in everyday practice: you are what you do
  • Nardi also argued that "activity theory proposes a strong notion of mediation—all human experience is shaped by the tools and sign systems we use."
  • Furthermore, she identifies "some of the main concerns of activity theory: [as] consciousness, the asymmetrical relation between people and things, and the role of artefacts in everyday life.
  • She explained that "a basic tenet of activity theory is that a notion of consciousness is central to a depiction of activity. Vygotsky described consciousness as a phenomenon that unifies attention, intention, memory, reasoning, and speech..." and "Activity theory, with its emphasis on the importance of motive and consciousness—which belongs only to humans—sees people and things as fundamentally different. People are not reduced to 'nodes' or 'agents' in a system; 'information processing' is not seen as something to be modelled in the same way for people and machines."
    Nardi argued that the field of Human-Computer Interaction has "largely ignored the study of artefacts, insisting on mental representations as the proper locus of study" and activity theory is seen as a way of addressing this deficit.

In a later work, Nardi et al in comparing activity theory with cognitive science, argue that "activity theory is above all a social theory of consciousness” and therefore “... activity theory wants to define consciousness, that is, all the mental functioning including remembering, deciding, classifying, generalising, abstracting and so forth, as a product of our social interactions with other people and of our use of tools.

For Activity Theorists "consciousness" seems to refer to any mental functioning, whereas most other approaches to psychology distinquish conscious from unconscious functions.