Representing Cognitive Activity in Complex Tasks

While cognitive theory has been recognised as essential for the analysis of Human-Computer Interaction, the representations that have been developed have been directed more towards theoretical purposes than practical application. To bridge the gap between theory and application, representations need to satisfy requirements for broad scope, a unified theoretical basis, and abstraction. Interacting Cognitive Subsystems (ICS) is proposed as a unified cognitive theory that can be used as the basis for such representations, and two approaches based upon the theory are described. One entails the description of Cognitive Task Models, which are a relatively complete representation of the cognitive activity required of a user in the course of an interaction. The other entails the production of less complete diagrammatic notations that are intended to provide support in small scale problem identification and resolution, and which can be applied across tasks, visual interface and sound interface issues, and can handle static and dynamic situations. While the former can be implemented in a production-rule expert system (ICSpert) and so does not require detailed modelling knowledge on the part of the analyst, the latter is a pencil and paper technique that does require theoretical knowledge, but which is intended to facilitate the acquisition of such knowledge in the interest of educating its users about the human aspects of HCI. The representations differ in the knowledge required for their use, in the support that they offer, and in the situations for which they are appropriate. They have been used to represent problems from experimental situations, core HCI scenarios, and ‘real world’ design projects. They share breadth of scope and abstraction, and their parent theory supports transfer of knowledge across domains of application and from older to newer technologies, and supports feedback between the domain of application and the domain of theory. Philip Barnard is a psychologist with an interest in theories of mental architecture and their application to complex tasks, emotion and a range of psychopathologies; he is on the scientific staff of the Medical Research Council's Cognition and Brain Sciences Unit. Jon May is a psychologist with an interest in the application of unified models of cognition to perception, particularly with regard to the effects of task and context; he is a Lecturer in the Department of Psychology at the University of Sheffield. Acknowledgements . We thank our partners in both Amodeus projects for their constant requirement that we explain ourselves more clearly, and in particular Anker Jørgensen and his students at Copenhagen University for supporting the development of the Diagrammatic Representations. Notes: Authors are in alphabetical order. Support . This work was carried out as part of the Amodeus-2 project, ESPRIT Basic Research Action 7040 funded by the Commission of the European Communities. Technical reports from the Amodeus project are available via the World Wide Web at http://www.mrc-cbu.cam.ac.uk/amodeus/ Representing Cognitive Activity