The cultural-historical theory of activity was initiated by a group of revolutionary Russian psychologists in the 1920s and 1930s. The approach was Lev Vygotsky (1896-1934) and his colleagues A. N. Leont'ev and A. R. Luria. They formulated a completely new theoretical concept to transcend the prevailing understanding of psychology which was then dominated by psychoanalysis and behaviorism. This new orientation was a model of artifact-mediated and object-oriented action (Vygotsky, 1978, p. 40).
The relationship between human agent and objects of environment is mediated by cultural means, tools and signs. Leont'ev introduced an emphasis on the division of labor as a fundamental historical process behind the evolution of mental functions. Mediated by tools, work is also "performed in conditions of joint, collective activity." The distinction between activity, action and operation became the basis of Leont'ev's model of activity.
Activity Theory was mainly a result of a larger effort to develop a new psychology based on Marxist philosophy, an effort which started soon after the Russian revolution of 1917. Several programs for restructuring psychology on a Marxist basis were formulated in the 20's and 30's, and very heated debates between proponents of different approaches were not uncommon at that time. One of the first postulates Soviet psychologists agreed upon was the so-called "principle of unity and inseparability of consciousness (i.e., human mind) and activity". The meaning of this principle was that human mind comes to exist, develops, and can only be understood within the context of meaningful, goal-oriented, and socially determined interaction between human beings and their material environment.Liam Bannon & Susanne Bødker
Activity Theory is not a "theory" in the strict interpretation of the term. It consists of a set of basic principles which constitute a general conceptual system which can be used as a foundation for more specific theories. These basic principles of Activity Theory include object-orientedness, the dual concepts of internalization/externalization, tool mediation, hierarchical structure of activity, and continuous development. The principle of object-orientedness states that human beings live in a reality which is objective in a broad sense; the things which constitute this reality have not only the properties which are considered objective according to natural sciences but socially/culturally defined properties as well.
Activity Theory differentiates between internal and external activities. The traditional notion of mental processes corresponds to internal activities. Activity Theory emphasizes that internal activities cannot be understood if they are analyzed separately, in isolation from external activities, because there are mutual transformations between these two kinds of activities: internalization and externalization It is the general context of activity (which includes both external and internal components) that determines when and why external activities become internal and vice versa.
The Activity Theory emphasis on social factors and on interaction between agents and their environments explains why the principle of tool mediation plays a central role within the approach. First of all, tools shape the way human beings interact with reality. And, according to the above principle of internalization / externalization, shaping external activities ultimately results in shaping internal ones. Second, tools usually reflect the experiences of other people who have tried to solve similar problems at an earlier time and invented/ modified the tool to make it more efficient. This experience is accumulated in the structural properties of tools (shape, material, etc.) as well as in the knowledge of how the tool should be used. Tools are created and transformed during the development of the activity itself and carry with them a particular culture - the historical remnants from that development. So, the use of tools is a means for the accumulation and transmission of social knowledge. It influences the nature, not only of external behavior, but also of the mental functioning of individuals.
In human activity theory, the basic unit of analysis is human (work) activity. Human activities are driven by certain needs where people wish to achieve a certain purpose. This activity is usually mediated by one or more instruments or tools (the concept of mediation is central to the whole theory).Martin Ryder
The carpenter uses a saw and a hammer to produce a house out of wood and the like, the teacher uses language, books, pictures, maps etc. to teach her pupils geography. However the carpenter building a house is not alone in the world. He works together with other carpenters, as well as with other building workers. The ensemble of carpenters divide their work between them. The ways of doing work, grounded in tradition and shared by a group of carpenters, nurses or the like, we call practice or praxis. When getting trained as a carpenter or nurse one gets to share this praxis. At the same time each individual who holds a praxis continues the praxis, and he or she changes it as well, by coming up with new ways of doing things. It is this praxis that allows us to talk about more than just individual skills, knowledge and judgement, and not just about a "generic" human being. In other words, we can talk about the appropriateness of a certain tool for a certain praxis.
Human beings mediate their activity by artifacts: The carpenter uses a hammer to drive a nail, the nurses use language and records to coordinate their actions towards the patients and each other, etc. Tools, means to divide work, norms and language can all be seen as artifacts for the activity: they are made by humans and they mediate the relations among human beings or between people and the material or product in different stages. One of the major contributions of Vygotsky was that he also viewed language and symbol systems as psychological tools for developing the human condition. Artifacts are there for us when we are introduced into a certain activity, but they are also a product of our activity, and as such they are constantly changed through the activity. This "mediation" is essential in the ways in which we can understand artifacts through activity theory.
In its simplest terms, an activity is defined as the engagement of a subject toward a certain goal or objective. In nature, an activity is typically unmediated. Picking a berry from a bush and eating it is a simple, unmediated activity that involves direct action between the subject and object. In most human contexts our activities are mediated through the use of culturally established instruments, including language, artifacts, and established procedures. Picking mushrooms in the forest and eating them is an activity that is ill-advised without some form of mediation. Our subject would prudently appropriate some prior knowledge - a field guide, prior education in mycology, the direct advice of an experienced mushroom forager, or some other embodiment of human experience with mushrooms. Some means is necessary to bring the prior experience of history into the current activity. Animals have only one world, the world of direct objects and situations, mediated only through instinct. Humans have the vicarious worlds of other humans that they can invoke into the present through the use of language and artifacts. (Luria, 1981)
An activity is undertaken by a human agent (subject) who is motivated toward the solution of a problem or purpose (object), and mediated by tools (artifacts) in collaboration with others (community). The structure of the activity is constrained by cultural factors including conventions (rules) and social strata (division of labor) within the context. Engeström calls attention to the mediational role of the community and that of social structures including the division of labor and established procedures. In our mushroom example, a more knowledgeable forager could serve in the capacity as foreman, dictating which mushrooms to pick and which to leave alone. More likely, the expert would serve in the capacity as a tutor or coach, explaining the criteria she uses to discriminate between the edible mushrooms and the poisonous. Or the necessary knowledge could come in the form of a structured set of rules which clearly specify the detailed procedures that must be followed in the selection of edible mushrooms. It is concievable to make use of some exotic instrument which can sample a piece of the mushroom and perform necessary chemical analyses to detect poisonous substances. The knowledge which is necessary in an activity system can emerge in any one or a combination of instruments, artifacts and mediational roles.
According to Vygotsky, a human individual never reacts merely directly (or merely with inborn reflects) to the environment. The relation between the human agent and the object is mediated by cultural means or artifacts. The basic types of these means are signs and tools. During socialization, an individual internalize, by participating in common activities with other humans the means of culture: language, theories, technical artifacts as well as norms and modes of acting. Thus consciousness doesn't exist situated inside the head of the individual but in the interaction - realized through material activity - between the individual and the objective forms of culture created by the labour of mankind.Maximina M. Freire
Later Activity theory developed further the ideas of Vygotsky. A.N. Leontjev, a disciple of Vygotsky stressed that activity is also socially mediated: consciousness and meaning are always formed in joint, collective activity (Leontjev 1978). As a result, the unit of analysis in studying human mediated activity, is an activity system, community of actors who have a common object of activity (Engeström 1987, Cole & Engeström 1994). In this model social mediatedness is characterized by division of labour and rules mediating the interaction between the individuals in the activity system. The collective activity system as unit of analysis connects the psychological, cultural and institutional perspective to analysis. The study of activity ceases to be psychology of an individual but instead focuses on the interaction between an individual, systems of artifacts and other individuals in historically developing institutional settings.
The attempt at correlating context, participants and texts as interactants in communicative events suggests the possibility of interpreting their interrelationship by applying the tri-stratal analysis of social activity (Leontiev, 1981: 59-69). This framework helps us to understand activities, actions and operations performed by participants and to reveal their motives, goals and instrumental conditions, respectively.Bonnie A. Nardi
For Leontiev, the concept of activity answers to a specific need of the active agent: it moves toward the object of this need and terminates when it is satisfied. Consequently, the concept of activity is necessarily connected with the concept of motive.
Activities are translated into reality through a specific or a set of actions which are subordinated to the idea of having a conscious goal. Comparatively, activities and actions are genuinely diverse realities which do not coincide: one action can be instrumental in realizing different activities; conversely, one motive can give rise to different goals and, accordingly, can produce different actions.
Actions are developed through operations which are concerned with conditions. The distinction between actions and operations emerges clearly in the case of actions involving tools: while actions are connected to conscious goals, operations are related to routinized behaviors performed automatically, without including the same level of consciousness.
Activity theory is 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 theory incorporates strong notions of intentionality, history, mediation, collaboration and development in constructing consciousness. 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. And what you do is firmly and inextricably embedded in the social matrix of which every person is an organic part. This social matrix is composed of people and artifacts. Artifacts may be physical tools or sign systems such as human language. Understanding the interpenetration of the individual, other people and artifacts in everyday activity is the challenge activity theory has set for itself.
In activity theory, artifacts are mediators of human thought and behavior; they do not occupy the same ontological space. People are not reduced to "nodes" or "agents" in a system; "information processing" is not seen as something to be modeled in the same way for people and machines. Activity theory proposes that activity cannot be understood without understanding the role of artifacts in everyday existence, activity theory is concerned with practice, that is, doing and activity, which significantly involve "the mastery of ...external devices and tools of labor activity".