Effects of Asymmetry between Design Models and User Models on Subjective Comprehension of User Interface

Abstract

This study attempted to discuss the design principles for enhancing usability in terms of asymmetry of mental models between users and designers. If the user model is asymmetrical to the design model, i.e., the degree of agreement between models is low and the user’s mental model is not compatible with the actual system, the user cannot operate the system properly, which may cause errors. The aim of this study was to investigate the characteristics of users who have asymmetrical mental models and identify what such users did not understand. Twenty-four subjects participated in an experiment that involved a digital camera operation task and mental model tests that measure the level of the agreement of the mental model construction in terms of functional and structural models. Initially, the participants were grouped based on mental model test scores: symmetrical mental model group (n = 17) and asymmetrical mental model group (n = 7). Then, the groups were compared in terms of performance and subjective comprehension. The comparison indicated that the symmetrical mental model group performed more quickly and accurately than the asymmetrical group. The results also confirmed that the asymmetrical mental model group had a lower level of comprehension in terms of understanding the device status, detecting and responding to device status changes, and understanding the hierarchical structure of the screen.

Development of Low-Fidelity Virtual Replicas of Products for Usability Testing

“…Another issue revealed in the pilot study was a mismatch between subjects' expectations of virtual object interactions and the results, as shown in Table 6, by a small percentage of subjects. Expectation mismatch can confuse and adjust how one responds [26,118]. Improvements will be made to the software architecture of the simulated object interactions to better align subject expectations with the functions of the simulation.…”

“…This paper will discuss a process used to create a low-fidelity usability test utilizing a CAD model. Enhanced use of CAD model in usability tests will expand capabilities to evaluate user experience and refine the design based on feedback, thereby reducing the potential for mismatch between user and designer expectations [26].…”