Distributed Cognition

In the theory of distributed cognition (DC) (Hollan et al., 2000; Halverson, 2002; Nardi, 1995) the main unit of analysis is the functional system. A functional system consists of the people and the resources used, and their relationship to each other within the work environment.

DC focuses on understanding interactions between people and technology to explain how cognition is distributed in the work setting. This distribution may be across members of the working group, across people and external resources, and across time (Hollan et al., 2000). A DC analysis of a certain work practice must include the functional system, the inputs and outputs of the functional system, the intermediate representational forms leading to the final outcome, the goal, the background of the activity, the available resources, and any environmental factors that contributes to the accomplishment of the task (Perry, 2003.)

The approach used by DC to understand these interactions between people and technology is to study the transformations undergone by representation states during the whole process. DC shows a clear emphasis on representation states and the importance of representation states to cognition. Representation states are not bound to material things, they may be mental representations in the minds of people, audio representations expressed by conversations, or physical movements like gestures. Representation states are transformed by tools. An idea in the mind may be transformed into a sketch by the use of paper and a pen. By describing a representation to another using the phone as a tool, for example, the representation is transformed to an audio presentation.

Cognitive activities refer to the computations taking place while representation states are propagated across media (i.e. individual memory, paper, or computer display) (Rogers and Ellis, 1994). Analysis of group work is put in the heart of the theory. Although a functional system may consist of one person, the general case involves a group and not simply a single individual. By taking the cognitive approach, DC recognizes the importance of knowledge building and knowledge propagation among the group. Lehtinen (2003) observed that designing applications that allow the use of cognitive tools and multiple representation forms, helps learners by reducing cognitive processing load, thereby allowing them to take on more challenging problems than otherwise possible. DC, like AT, focuses on the importance of identifying breakdown situations and the importance of such situations to learning and sharing knowledge among group members (Rogers and Ellis, 1994; Norman, 1993).

DC and the design of collaborative learning applications

The way I have used DC to guide design of collaborative learning tools is based on the two main concepts of

• Representation states, where the different representations states of the problem throughout the task are identified
• The tools, where the tools required to transform the representation states in order to proceed through the task are identified

Having introduced the concepts of representation states and how tools are used to transform these states, it is now possible to explain the notion of externalization. Externalization refers to making the thinking of the people involved visible to others (i.e., from an internalized representation state in the mind to an external representation either as speech, or as a tangible/visible representation). Externalization is specially important for collaborative learning applications because it induces task-related discussions that have a number of positive learning consequences. Moreover, the more the group work is made visible, the easier it is for teachers or supervisors to asses and provide adequate support to the collaborators. It is important to provide a full set of tools that make it possible for the collaborators to externalize all task-related thoughts (i.e., transform task-related representations from on form to another).