Previous research
People who have looked into making websites work for people with intellectual disabilities have said
it’s difficult for this group to work with text
web users should be able to listen to words, as well as read them
web pages should include a small amount of words
it should be clear and obvious where buttons will take you
pictures and text should be big
words should be clear and simple
Very little research has been carried out on web accessibility and intellectual disability.
Peter Williams and David Nicholas summarise some of this work in ‘Testing the usability of information technology applications with learners with special educational needs’ in The Journal of Research in Special Educational Needs, volume 6, number 1, 2006.
Processing text
Harrysson and others carried out a study with a small group of intellectually disabled people aged 15-44.
They found that these users were adept at navigation, but had difficulty with text input. They concluded that 'the processing of text can impede accessibility to the Internet for people with cognitive disabilities’.
(How people with developmental disabilities navigate the Internet’, British Journal of Special Education, 31(3))
Expert panel results
Brown and others examined the usability of an interactive multimedia learning environment for people with intellectual disabilities, consulting an expert panel.
They produced the following accessibility guidelines (and others) as a result:
Accessibility: provide a speech alternative of all buttons and text.
Navigation: provide a menu that allows the user to jump to anywhere at any time and an exit button.
Pedagogic structure: provide regular rewards, reinforcement and tests.
Aesthetics: use a maximum of three sentences per page.
(Design guidelines for interactive multimedia learning environments to promote social inclusion’, Disability and Rehabilitation 24 (11-12))
On dyslexia
The Disability Rights Commission commissioned research into the accessibility of websites. They found the following key problems affecting people with the specific learning difficulty of dyslexia:
Unclear and confusing layout of pages
Confusing and disorienting navigation mechanisms
Inappropriate use of colours and poor contrast between content and background
Graphics and text too small
Complicated language or terminology
(The Web: Access and Inclusion for Disabled People’ a formal investigation conducted by the DRC)