Date of Award

Fall 2015

Document Type


Degree Name

Master of Science (MS)



Committee Director

James P. Bliss

Committee Member

John C. Brill

Committee Member

Cathy Lau-Barraco


Warfighters must rely on lengthy instruction manuals when asked to perform tasks in critical environments. These instruction manuals are predominantly written in text and rarely include images. Several theoretical frameworks, including the Pictorial Superiority Effect, posit images to be more effective forms of instruction for short-term memory recall tasks. It is unclear whether pictures are superior forms of instruction for use in tasks with potential life-threatening consequences. Recently, studies have attempted to define and manipulate task criticality to determine the effects a critical scenario may have on operator performance. Findings have been equivocal, perhaps because of the ambiguity associated with the definition of task criticality. The purpose of the current work was to determine whether images or textual descriptions were more effective forms of instruction for a target search task in a critical scenario (defined as a task with life-threatening consequences). Forty participants were asked to participate in this study. Twenty participants had military deployment experience and twenty participants were students with no deployment experience. Participants were asked to traverse a virtual battlefield environment to search for targets; half of which were presented with images and the other half with textual descriptions. Participants searched for targets under conditions of both low and high task criticality. This study used a 2 × 2 × 2 quasi-experimental mixed design and results were analyzed using a series of mixed ANOVAs. The results showed both samples collected more pictorial targets in the high criticality condition than in the low criticality condition. Participants collected pictorial targets faster than lexical targets, and military participants took longer to locate textual targets in the high criticality condition. Military personnel and students made more errors searching for lexical targets, and military overall made more errors than students in both conditions. Military participants experienced higher cognitive workload in the high criticality condition. These results lend credence to the Pictorial Superiority Effect, Dual-Coding Theory, and the Critical Decision Method. As pictorial information may lower cognitive resource demand, these results suggest that warfighters and other operators should be presented with pictorial information during a critical task to increase performance and minimize errors.