Mental Models, Performance and Usability of a Complex Interactive System: The Case of Twitter

This work presents the study of a complex interactive system (Twitter) and the analysis of the relation between people´s mental models, performance and usability perceptions. Participants were asked to perform a number of activities with Twitter and to draw graphical representations of their mental model about it. We identified three typical Mental Model Styles (MMS) used to describe Twitter. With these styles in mind, we conducted two analyses, one based only on the MMS and the other one based on the MMS and the expertise. We found that the level of expertise had a major impact on performance rather than the mental model style defining the understanding about the system. Furthermore, we found that usability perception was affected by both, the level of expertise and the mental model style.