Modeling the Cognitive Complexity of Visual Displays

An approach for measuring the cognitive complexity of visual display formats is presented. The approach involves modeling both the knowledge that can be extracted from a format and the knowledge an operator brings to a task. A semantic network formalism is developed to capture task-relevant knowledge, from which four orthogonal predictor measures of cognitive complexity are derived. In an experiment, seven different avionic missions, performed with the aid of a horizontal situation display, were studied, and three of the predictor measures were found to correlate significantly with observed task difficulty. The results indicate that a semantic network formalism can be used to produce an objective metric of format quality in terms of cognitive complexity.