Information complexity in air traffic control displays

Air traffic controllers use visual displays to interact with various automation systems. Information complexity in those systems may cause controllers to miss or misinterpret visual data, thereby reducing safety. The purpose of this study was to answer three basic questions: 1) What constitutes information complexity in automation displays? 2) How complex is "too complex" for controllers? 3) Can we objectively measure information complexity in the displays? We first developed a general framework for measuring information complexity. The framework reduces the concept of complexity into three underlying factors: quantity, variety, and the relations between basic information elements; each factor is evaluated at three generic stages of human information processing: perception, cognition, and action. We then developed nine metrics of display complexity, each measuring the effects of a complexity factor on information processing at a given stage. These metrics provide an objective method to evaluate automation displays for acquisition and design prototypes.