Abstract :
This study investigated the dynamic process of people constructing mental models of MedlinePlus, a medical information web space, during their interaction with the system. Thirty-eight participants participated in the study. Their mental models of MedlinePlus were measured by a concept listing protocol and an interview method at three time points: after they freely explored the system for 5 min (T1), after the first search session (T2), and after the second search session (T3). The analysis revealed that participants constructed their mental models of MedlinePlus based on the schemas that they have of information-rich web spaces. The model construction process involved changes and development in three parallel dimensions: cognition, emotion, and behavior. The development is enabled and coordinated by three mental activities: assimilating new concepts, modifying existing concepts, and phasing out previously perceived concepts. Furthermore, mental model construction is not only a function of usersʹ internal cognition, but also affected by external cognitive structures, including the system, system feedback, and tasks. Mental model construction is also a process distributed over time. The results suggested that mental models could serve as a framework for guiding user research and system design. The dynamic nature of the mental models indicated that an iterative approach needs to be adopted.