Activities can be broken down into goal-directed actions that have to be undertaken in order to satisfy the object. Actions are conscious and are implemented through automatic operations. Activity Theory maintains that the elements of activity are not fixed but can change dynamically as conditions change. Instead it encompasses the socially and culturally determined properties also. Internalisation relates to the human being's ability to imagine, consider alternative approaches to a problem, perform mental simulations.
Externalisation transforms an internalised action into an external one.
Mediation Human activity is mediated by artefacts tools both internal and external. These tools may be signs, language, instruments or machines. They are created by people and effect control over behaviour. Artefacts have an associated culture and history and permanence that exists across time and space. Development Activity Theory requires that the way a human interacts with reality should be analysed within the context of development.