The Mechanics of Comprehension and Comprehension of Mechanics

When people solve mechanical problems, such as troubleshooting, designing, or understanding the operation of mechanical systems, they typically operate on visual displays of these systems—either the machine itself or a schematic diagram of the machine. If the display is central to their problem-solving process, we can assume that their eye fixations on the display indicate the information that they are processing at each stage of the problem-solving process (Just & Carpenter, 1976). Given this assumption, eye-fixation data has provided important insight into cognitive tasks such as mental rotation (Just & Carpenter, 1976, 1985), sentence-picture verification (Just & Carpenter, 1976) and visual analogies (Carpenter, Just, & Shell, 1990). This chapter presents research in which eye-fixation data was used to study a more complex cognitive task, the task of understanding a mechanical system.