Applying User Interface-Operable 3D Digital Prototypes to Human-Centered Design of Information Appliances Available to Purchase

One of the critical issues of realizing human centered design (HCD) for information appliances is how to efficiently find the weakness of usability of the user interfaces (UI). At present, user test is the most reliable method of evaluating usability of UI. But executing user-test costs much due to fabrication of physical prototypes, securing of test subjects and facilities and the manual-based analysis of the test results. To solve the problems, we propose a computer-supported environment for testing and usability assessment for human centered-design of information appliances in the paper. In the environment, UI-operable 3D digital prototypes can be designed and used for user tests instead of physical prototypes, and the test results can be automatically analyzed to clarify the weak points of the UI design. UI-operable 3D digital prototypes can be modeled by integrating the state-transition-based UI behavior model with 3D CAD models of the housings. A function of graphically displaying user’s operational history helps the designers identify which portions in the UI specification induce wrong operations of users. A function of indicating digital questionnaire based on cognitive walkthrough method also enables them to reveal causes of the wrong operations and to clarify point of redesign. Comparison of the test results using different types of digital prototypes showed that the proposed UI-operable 3D digital prototype could fully replace the physical prototype in early design stage.