Which Diversity? Expanding the Gap Model of Disability for Digital Information Systems

In this paper, we extend the gap model of disability that supports digital equipment and cyber-physical situational variations. We explore an alternative approach to visualizing and understanding disability that takes into account the diversity of personal abilities, the diversity of digital equipment and equally important, the situation (environmental, psychological, and digital) in which the information system is used. The most important implications of this work are twofold. First, this work will contribute to the need for Universal Design to take into account not only the diversity of abilities and impairments of the users that are tangible and recognizable in the physical environment, but also the diversity of digital equipment and usage situations. Second, as part of the systems development cycle, in user testing of digital services, this work highlights the essential need to not only involve a diverse set of users, but also to conduct testing in diverse digital environments (smartphones, tablets, laptops and desktop PCs), and in diverse realistic usage scenarios, including strong sunlight or low light situation, as well as tired, alert, stressed or distracted, and slow network. The proposed model attempts to give a more holistic view and promote a more comprehensive understanding of the disabilities that can occur during use of digital services or mediated communication in daily life.