Accessibility of services on the web

Table of contents Statistics Definitions Different kinds of disabilities Solutions for accessibility

Statistics 21.1% of people with vision problems have Internet access 27.2% of people with hearing problems 22.5% of people with difficulty using hands 42.2% of people with a learning disability => 56.7% of non-disabled people have Internet access Survey realised in the USA in 2001

Definition Disability: ”Disability is a physical or mental impairment which has an effect on the ability to carry out normal day-to-day activities” Accessibility: ”Accessibility functionality makes content resources usable by persons with disabilities” Web accessibility: ”Web accessibility refers to the practice of making websites usable by people of all abilities and disabilities”

Different kinds of disabilities Visual (blindness, poor eyesight and colour blindness)‏ Aural (deafness and impaired hearing)‏ Cognitive (dementia and dyslexia)‏ Physical or Motor (muscular dystrophy, cerebral palsy)‏

W3C W3C (World Wide Web Consortium)‏ Founded in 1994 by Tim Berners-Lee Objective: development of web standards and guidelines. Examples: CSS, HTML, XHTML, SOAP, XML, XForms

WAI WAI (Web Accessibility Initiative)‏ Has been launched by W3C in 1997 Objective: creation of international standards and guidelines in order to improve the accessibility of web for people with disabilities

Tools for blind people Screenreader  Text-to-spreech  Braille output device Oralux: Linux distribution

Solutions for visual disability Use CSS Use headings (H1, H2, H3, H4)‏ All informational images use ALT text Provide a site map Make sure that the text can be resized Efficient contrast between background and foreground colours

Solutions for aural disability For any audio content => Provide subtitles or written transcripts

Solutions for cognitive disability Use simple and easy language (non technical)‏ Avoid using words in their non-literal sense Avoid using abstractions Use large headings Do not use scrolling text

Solutions for physical or motor disability These users do not use mouse but only keyboard  Use vertical navigation links Avoid flickering between 2 and 55 Hz (epileptic users)‏

Conclusion/Interpretation Solutions are generally easy to implement Solutions are generally cheap Solutions are usefull for disabled and also valid users