Effects of Visual Complexity Levels and Information Decluttering Methods for Cockpit Displays on Human Search Performance

Clutter problem of modern cockpit displays can occur frequently due to a large amount of information. So, decluttering less important information is required to minimize search time to find target information and prevent human error in interpreting display information. This study is to compare human search performance by visual complexity levels and decluttering methods of cockpit displays. Visual complexity of cockpit displays was designed to be three levels (High, medium, and low) by combining four design variables (number of stimuli, number of colors, number of icons, and variance of divisions) affecting visual complexity. A threat scoring equation was developed to determine what information to be decluttered and four decluttering methods (removal, dimming, dotting, and small sizing) were used to figure out how to declutter the information effectively. Human search performance was measured through search time of visual search task in terms of speed and number of hits of signal detection task in terms of accuracy. The main effect of visual complexity levels and the interaction effect were not significant in both search time and number of hits. Meanwhile, the main effect of decluttering methods was significant in search time. Especially, dotting was the most effective decluttering method in terms of speed and accuracy of human perception performance. The results of this study can be applied to information processing of cockpit displays and then contribute to improve pilot situation awareness.