Opens by outlining the general failure of theoretical psychology to apply to HCI. HCI is generally developed from practical knowledge. The problem is especially related to the psychological theory of information processing, deriving from cognitive science. Kuutti describes a movement in HCI that reacts against the symbolic/Cartesian model.

He examines Liam Bannon, who presented a critique of Human Factors (as likening humans to components to factor into a human-machine system), and further criticizes HCI as exploring only inexperienced users. This critique relates back to the idea of everyday life and practice. Experienced users make use of emergent practices that may augment or subvert the original model.

HCI is composed of three levels. The first is oriented toward ergonomics, perception and motor skills. The second is concerned with information processing and conceptual psychology. The last is an emerging level that addresses deeper complexity, and is the target for applying activity theory.

As background, activity theory originates in Kant and Hegel. This German philosophy developed against objective empiricism, the idea that meaning is external and may be discovered through experience, and replaced it with constructivism, where meaning is actively constructed. This idea was later adopted by Marx and Engels who applied construction and activity to political ends. Activity was finally developed by Vygotsky and his school of psychology. Kuutti suggests that Mead’s symbolic interaction (which led to Goffman) also followed a similar vein.

An activity is the basic unit of analysis. The idea is to define an activity as a subset of actions that has a minimal meaningful context. Activities are mediated, and are also permeable and flexible structures. It also provides an interesting approach to tool use. Tools are media that enable activities, but they limit the user in things that do not belong to that activity. This is especially important if we consider tools or mediators to be more than physical objects. Mediation can be through environment or other contexts. In this sense, the limiting nature of tools reflects pattern matching in phenomenology as well as the notion of keying in sociology.

Activity also works with the idea of a community formed around activities and the mediating object. This establishes the notion of a collaborative activity, where members may have different roles. Kuutti calls the division between these roles a division of labor, but I would argue that activity is not dependent on labor.

Kuutti does relate activity to planning, but as a step that is about modeling, not outlining the action. The initial phase of an activity is orientation, during which the agent models the world into consciousness. The execution of an activity is composed of “fluent” engagement with the world, which is composed of operations. This model allows for a hierarchical model of activity that derives from learning and practice. For a novice learning how to drive a car, the process of changing the gearbox is a highly conscious activity that requires a lot of attention to the individual elements of the task, but later on, these operations become fluent elements and moving the gearbox is merely an action in the larger activity of driving. Kuuti does not examine this hierarchy, though, and seems to assert that activity only happens at this higher level.

Activity relates to HCI by looking at how people go about using computers for activities. This exposes some of the ways in which traditional information processing psychology has failed to help HCI. Notably, it addresses the issues of complexity and use and practice.