Modeling the Cognitive Content of Displays

An approach for measuring the cognitive complexity of visual displays is discussed and applied to a dynamic display of avionic information. A semantic network formalism is used to model two interrelated knowledge systems, world knowledge and display knowledge. The information the operator receives during training about the general display format characteristics and the task requirements, along with other previously stored information, constitutes world knowledge. The semantic content of a particular configuration of information encountered during task performance constitutes display knowledge. Four orthogonal predictor measures of cognitive complexity were derived from the networks. In an experiment three of the orthogonal predictors were significantly correlated with task performance. After averaging across operators, the three significant predictors accounted for 99% of the variation of display effectiveness. Results indicate that a model of cognitive complexity based on a semantic network formalism may provide a useful technique for quantitatively evaluating the quality of competing display format concepts.