Disability users' evaluation of the web accessibility of SNS

Social network service (SNS) is an effective communication tool for the community of disabled people. However, there is a general paucity of research on web accessibility of SNSs. This study investigates web accessibility of four SNSs that are most popular among disabled people: Facebook, Twitter, Me2day, and Yozm. Eight disabled individuals were selected according to the type of disability: two with total blindness, two with low vision, two with brain lesions, and two with an upper extremity disability. The subjects were asked to perform four navigationrelated tasks and ten general tasks for each SNS. The success rate of their performances and user satisfaction levels were then measured. The four SNSs, on average, attained a task success rate of 73 % and a user satisfaction score of 3.1 points (max. = 5), indicating that the disabled participants found the websites generally inconvenient. As a pioneering evaluative study of the web accessibility of major SNS sites for the disabled, this research contributes to both theory and practice.