Study of symbols coding in airway facilities

An evaluation of three symbol-coding techniques for depicting Federal Aviat ion Administration (FAA) facilities and services was conducted. Twenty-eigh t Airway Facilities (AF) specialists and managers participated in the study . The effect of using redundant coding versus two different single coding t echniques on both subjective and objective performance was studied. The eva luation considered the usage of pictorial symbols, alpha-numeric symbols (b oth are single coding techniques), and a combination of pictorial and alpha -numeric symbols (redundant coding) on future AF systems and displays. A co mprehensive evaluation technique measuring subjective ratings and objective variables in recall and recognition tasks, was used. Symbol training was p rovided and used as a variable. Two modes of training, accuracy, speed of r esponse, and subjective ratings were the dependent measures. The entire eva luation was conducted using an exclusively developed software package, Evaluation results indicated significant ease of training with alpha-numeri c and combination symbols and significantly faster response times for picto rial and combination symbols. Combination symbols had the highest subjectiv e rating. Combination symbols using redundant coding had the best overall p erformance both subjectively and objectively. Prior familiarity with some o f the FAA facilities and services did not affect speed or accuracy of perfo rmance.