The Effects of Visual Information on Users' Mental Models: An Evaluation of Pathfinder Analysis as a Measure of Icon Usability.

Abstract

Research has shown that individuals' knowledge structures change as a result of learning and experience. This article investigates the possibility that the content of graphical user interfaces can play a role in determining the nature of the knowledge structures users develop. Users employed either concrete, abstract, or arbitrary icon sets in a computer-based problem-solving task. The effects of these icons were assessed using standard measures of performance. On the basis of the assumption that users' mental models should be better if appropriate icons were presented on the interface, Pathfinder analysis was used to elicit users' knowledge structures as they gained experience with the interface. The efficacy of this measure was then compared with performance measures. Our findings show that users' knowledge structures do depend on the nature of the graphical information presented at the interface but do not rely as much on the use of the visual metaphor as previously thought. Although most measures were sensitive to initial differences between icon sets, only some measures were sensitive to the long-term differences that remained after users had gained experience with the icon set. The implications of these findings for interface design are discussed.