Making mental models manifest

A study was conducted to determine what factors affect how humans detect correlation when forming mental models of complex systems. Using a paradigm that elicits the subject's mental model of a system by the subject's reconfiguration of the display, the authors conducted four experiments that illustrate humans' ability and factors affecting their ability to detect correlation in a dynamic display. It is shown that subjects can detect correlation in a dynamic system and that lowering the correlation makes detecting the correlation progressively more difficult. The data, combined with the subjects' comments, shows that the strategies adopted by the subjects govern their ability to detect correlation. The strategies adopted depend on the degree of correlation and the type of movement. Correlation predisposed subjects to discover grouping by either pairwise comparison (in the case of low correlation) or global search (in the case of high correlation). The type of movement, on the other hand, predisposed subjects to group bars by height (in the case of random walk movement) or correlation (in the case of Gaussian mean zero movement). Generally, this study forms the beginning of a research program investigating the factors that guide operators in generating mental models of complex systems.>