A heuristic checklist for an accessible smartphone interface design

Smartphone technology has evolved into a multi-functional device with advanced capabilities, but this mobile technology remains inaccessible to many individuals with visual impairments or upper extremity disabilities. This paper provides a heuristic checklist for accessible smartphone interface design, developed through reviewing existing design standards and guidelines and validating these guidelines with user involvement. Specifically, a set of preliminary user requirements (59 items) was extracted from existing standards, guidelines, and user requirements regarding mobile handheld device accessibility. Subsequently, the requirement set was filtered using a participatory method and then integrated to create an operational version of design guidelines. These guidelines were then used in a heuristic evaluation and usability testing on high-fidelity prototypes produced by a commercial manufacturer. A heuristic checklist for designing accessible smartphones was formed, which may also be applicable to other touchscreen handheld devices (e.g., printer screen) in terms of accessibility features. The initial set of 59 user requirements was re-organized into 44 statements in six general categories: mechanical controls, display, speech and general operation controls, audio feedback controls, touch-operated controls, and others. Using results from both qualitative and quantitative methods provides support, though with some limitations, for this accessibility checklist. This checklist is intended as a practical design support tool for use in early design phases of handheld products. A number of challenges and limitations are discussed as well.