User Evaluation of the Smartphone Screen Reader VoiceOver with Visually Disabled Participants

Touchscreen assistive technology is designed to support speech interaction between visually disabled people and mobile devices, allowing hand gestures to interact with a touch user interface. In a global perspective, the World Health Organisation estimates that around 285 million people are visually disabled with 2/3 of them over 50 years old. This paper presents the user evaluation of VoiceOver, a built-in screen reader in Apple Inc. products, with a detailed analysis of the gesture interaction, familiarity and training by visually disabled users and the system response. Six participants with prescribed visual disability took part in the tests in a usability laboratory under controlled conditions. Data were collected and analysed using a mixed methods approach, with quantitative and qualitative measures. The results showed that the participants found most of the hand gestures easy to perform, although they reported inconsistent responses and lack of information associated to several functionalities. User training on each gesture was reported as key to allow participants to perform certain difficult or unknown gestures. The paper also reports on how to perform mobile device user evaluations in a laboratory environment and provides recommendations on technical and physical infrastructure.