Disabled and elderly populations may not fully appreciate the benefits of advanced technologies and every-day products due to accessibility issues. However, the diverse characteristics of disabled and elderly users make conducting user research a challenging task for stakeholders who oversee the needs of developing accessible products. They need a tool providing rich information to empathize with the disabled and elderly users, instead of standards and documents without detailed explanation of real-world applications. Therefore, this study aims to identify accessibility issues based on the interview and observation data from 52 people with different disabilities and ages. We developed eight personas representing four different user groups under the context of home appliance usage: visually impaired, hearing impaired, spinal-cord impaired, and elderly. Each persona takes a role as a tool to understand the target users and has a persona card representing their task barriers, frustrations, needs, and quotations along with a cartoonized character. In this study, we address two common accessibility issues and two persona-specific issues within each user group. The issues are presented in stakeholder’s language personas to help them comprehend and empathize with their users.

To develop a flexible display, smartphones with edge screens with curved displays on both sides of the main screen have been used widely. Considering that small differences in the form of smartphones, such as length, width, and thickness, could affect user experience, the effects of the curvature of the edge screen should be identified. This study aimed to investigate the effects of the curvature of edge screens on subjective feelings of smartphone users and to find out the optimal curvature. In the experiment, four nonfunctional samples with different radii of curvature (4R/6R/8R/10R) were used as samples, and participants evaluated the five subjective feelings: grip/control comfort, front/side visibility, and stability of the samples with four usage patterns. Our results revealed that 8R is the optimal curvature for the edge screen based on subjective feelings in smartphone usage. Moreover, the effect of the curvature of the edge screen on grip comfort and control comfort varied according to the usage patterns. The results of this study can be applied to design of the curvature of edge screens in smartphones and it is expected that it will contribute to improvement of users’ satisfaction.

The rapid growth of the electric scooter (e-Scooter) market and its increasing urban use necessitate research into rider behavioral patterns and their impact on traffic safety. This study aims to design and validate an e-scooter rider behavior questionnaire (eSRBQ) to address this need. The eSRBQ was validated based on established tools like the Driver Behavior Questionnaire (DBQ) and the Cyclist Behavior Questionnaire (CBQ). A sample of 445 participants completed the eSRBQ, which comprised three factors: violations, errors, and positive behaviors. Confirmatory factor analysis (CFA) validated the questionnaire’s structure. The eSRBQ demonstrated good fit indices (Chi-squared/ df = 3.651, SRMR = 0.047, RMSEA = 0.077, CFI = 0.941, TLI = 0.932) and high internal consistency (Cronbach’s alpha > .7 for all factors). The study found significant differences in violations, errors, and positive behaviors based on collision history. Age and riding frequency also influenced behavior, with younger and less frequent riders displaying more violations. These findings highlight the necessity for targeted safety interventions and continuous monitoring of e-scooter rider behavior as their use expands. This study contributes to urban transportation safety by providing a validated tool for assessing e-scooter rider behavior and identifying critical factors for improving road safety.

Since the comfort feeling and satisfaction of a toilet seat is important for the defecation, we investigated the design parameters and affective attributes for toilet seats, and developed the affective model that explains the level of customer satisfaction. To achieve, objective measurements of design parameters and total 19 number of relevant affective attributes including appropriateness of each design parameter were collected from literature review and user interview. Then, a subjective experiment was conducted on five different toilet seat samples. As a result, 6 factors of surface and fatigue, appropriateness of toilet size, accessibility, immaculateness, centroid, and physical tensity were revealed by factor analysis. An affective model for seat comfort was also developed by regression analysis, and the relationships between each factor and design parameters were investigated through correlation analysis. This study is expected to contribute in improvement of toilet seat comfort as a preliminary study.

As home appliance interfaces become increasingly digitalized, users with visual impairment or spinal cord injury (SCI) face growing barriers to operating essential household devices. This study examines two prototype designs intended to improve accessibility: an acrylic panel with engraved grooves and Braille markings for washing machine touch panels, and a swing button that transforms pushing into a top-down pressing motion for microwave doors. Nine participants (five with visual impairment; four with SCI) evaluated the prototypes using a study-specific questionnaire combining Likert-scale and open-ended items. Both prototypes improved tactile guidance, reduced unintended activations, and enhanced usability within reachable ranges; an unexpected benefit was reduced glare for wheelchair users. However, tactile cues alone were insufficient for visually impaired users, who emphasized the need for voice feedback. These preliminary findings, though limited by sample size, support integrating accessibility into mainstream appliances rather than relegating it to specific products.