Abstract.No two persons are alike. We usually ignore this diversity as we have the capability to adapt and, without noticing, become experts in interfaces that were probably misadjusted to begin with. This adaptation is not always at the user's reach. One neglected group is the blind. Age of blindness onset, age, cognitive, and sensory abilities are some characteristics that diverge between users. Regardless, all are presented with the same methods ignoring their capabilities and needs. Interaction with mobile devices is highly visually demanding which widens the gap between blind people. Herein, we present studies performed with 13 blind people consisting on key acquisition tasks with 10 mobile devices. Results show that different capability levels have significant impact on user performance and that this impact is related with the device and its demands. It is paramount to understand mobile interaction demands and relate them with the users' capabilities, towards inclusive design.

Mobile devices are designed mostly to fit users with no particular disability. Tactile affordances are neglected at the expense of more attractive stylish interfaces and assistive solutions are stereotypical, also facing disabilities with a narrow perspective. A blind user is presented with screen reading software to overcome the inability to receive feedback from the device. However, these solutions go only half-way. In the absence of sight other capabilities stand up. Above all, the sense of touch plays an essential role while interacting with physical keypads. To empower these users, a deeper understanding of their capabilities and how they relate with technology is mandatory. We propose a user-product compatibility approach, taking in account that blind users have different tactile attributes. We expect to correlate the user's tactile sensitivity and keypad demands, enabling informed keypad design and selection.