Towards a unified definition of web accessibility

To better understand what researchers and practitioners consider to be the key components of the definition of web accessibility and to propose a unified definition of web accessibility, we conducted an analysis of 50 definitions of web accessibility. The definitions were drawn from a range of books, papers, standards, guidelines and online sources, aimed at both practitioners and researchers, from the across the time period of web accessibility work, from 1996 to 2014 and from authors in 21 different countries. The analysis extracted six core concepts that are used in many definitions, which are incorporated into a unified definition of web accessibility as "all people, particularly disabled and older people, can use websites in a range of contexts of use, including mainstream and assistive technologies; to achieve this, websites need to be designed and developed to support usability across these contexts".