Modelling cognitive processes of experienced air traffic controllers.

A model of the cognitive activities of experienced air traffic controllers is presented as an example of the challenging theoretical task to model mental processes in a dynamic task environment. Owing to the continuous changes in the task environment and the demand for the temporal co-ordination of activities in air traffic control, the model pays special attention to the mental representation of the situation. This unit of the model plays a salient role in maintaining situational awareness, in anticipating future states, and in co-ordinating simultaneously ongoing events. The assumptions about the mental representation of the changing task environment are discussed within the mental model approach. Its realization within the proposed model is outlined. The model has been developed on the basis of experimental research with air traffic controllers. Brief outlines of the experiments on information intake, and the mental representation as examples of the empirical investigation are presented. In an experiment on information intake, controllers with different levels of experience had to control a traffic scenario while the information on the radar screen and on the flight-strips were masked. The frequencies of unmasking showed that the controller's picture is built up by means of a considerable reduction of information regardless of the level of experience. However, less experienced controllers used more planning data, especially information needed for short-term anticipation. A card-sorting task was used to investigate the underlying dimensions for situation assessment. A measure for correspondence between classifications and multidimensional scaling established that situation assessment is based not only on anticipation, but also on the evaluation of further information processing requirements. The influence of the empirical results on the model is discussed.