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Accessibility Hugh Lunnon, Jo Castle and Aidan McGinley What is Accessibility? An accessible product or service is one which can be used by all its intended users Accessibility is most commonly discussed in relation to people with disabilities

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Hugh Lunnon, Jo Castle and Aidan McGinley

what is accessibility
What is Accessibility?
  • An accessible product or service is one which can be used by all its intended users
  • Accessibility is most commonly discussed in relation to people with disabilities
  • Accessibility barriers occur when the design of the technology fails to allow for the variations in users' abilities.
accessibility goals
Accessibility goals
  • All users are able to perceive and understand the controls, instructions and outputs
  • All users are able to reach and manipulate the controls, inputs and outputs
  • The user interface is consistent across functions, devices and repeated use
  • For users who still cannot use the service, an equivalent alternative service is available
web accessibility
Web Accessibility
  • Web sites and applications
    • that people with disabilities can perceive, understand, navigate, and interact with;
  • Web browsers and media players
    • that can be used effectively by people with disabilities, and
    • that work well with assistive technologies that some people with disabilities use to access the Web;
  • Web authoring tools, and evolving Web technologies
    • that support production of accessible Web content and Web sites, and that can be used effectively by people with disabilities.
impact of the web on people with disabilities
Impact of the Web on People with Disabilities
  • The Web is becoming a key resource for:
    • news, information, commerce, entertainment,
    • classroom education, distance learning,
    • job searching, workplace interaction,
    • civic participation, government services.
  • It is displacing traditional sources of information and interaction --
    • schools, libraries, print materials, discourse of the workplace;
    • some of the traditional resources were accessible; some not.
  • An accessible Web means unprecedented access to information for people with disabilities.
web accessibility is a cross disability issue
Web Accessibility is a Cross-Disability Issue
  • Examples of design requirements for people with different kinds of disabilities include:
  • Visual:
    • described graphics or video;
    • well marked-up tables or frames;
    • keyboard support, screen reader compatibility;
  • Hearing:
    • captioning for audio, supplemental illustration;
  • Physical, Speech:
    • keyboard or single-switch support;
    • alternatives for speech input on voice portals;
  • Cognitive, Neurological:
    • consistent navigation, appropriate language level;
    • illustration; no flickering or strobing designs
accessibility contributes to universal design design for all
Accessibility Contributes to Universal Design (Design for All)
  • Accessible Web design can contribute to better design for other users:
  • Multi-modality (support for visual, auditory, tactile access) benefits users of:
    • mobile phones with small display screens, Web-TV, kiosks.
  • Multi-modality increases usability of Web sites in different situations:
    • low bandwidth (images are slow to download);
    • noisy environments (difficult to hear the audio);
    • screen-glare (difficult to see the screen);
    • driving (eyes and hands are "busy").
  • Redundant text/audio/video can support:
    • different learning styles; low literacy levels; second-language access.
  • Style sheets can support:
    • more efficient page transmission and site maintenance.
  • Captioning of audio files supports:
    • better machine indexing of content; faster searching of content.
tips for accessible websites
Tips for Accessible Websites
  • Images & animations: Use the alt attribute to describe the function of each visual.
  • Image maps. Use the client-side map and text for hotspots.
  • Multimedia. Provide captioning and transcripts of audio, and descriptions of video.
  • Hypertext links. Use text that makes sense when read out of context. For example, avoid "click here."
  • Page organization. Use headings, lists, and consistent structure. Use CSS for layout and style where possible.
  • Graphs & charts. Summarize or use the longdesc attribute.
  • Scripts, applets, & plug-ins. Provide alternative content in case active features are inaccessible or unsupported.
  • Frames. Use the noframes element and meaningful titles.
  • Tables. Make line-by-line reading sensible. Summarize.
  • Check your work. Validate. Use tools, checklist, and guidelines at
tips for checking the accessibility of your website
Tips for Checking the Accessibility of Your Website
  • Turn off graphics & sounds
  • Check the contrast by viewing the page in greyscale
  • Turn off style sheets
  • Turn off scripts, applets, or other programmatic objects
  • Use the largest font size allowed by a browser
  • Use Text based browser like Lynx (
designing accessible user interfaces
Designing Accessible User Interfaces
  • Points to consider
    • Obstacles to Accessibility
    • Impact on system design
    • Access Technologies
  • Design guidelines
    • Overview
    • Examples
    • Issues and Trade-offs
obstacles to accessibility
Obstacles to Accessibility
  • Disabilities
    • Visual impairments & blindness
    • Hearing
    • Cognitive
    • Physical
    • Neurological
obstacles to accessibility 2
Obstacles to Accessibility (2)
  • Technological
    • Lack of technological updates
    • Slow processing times
  • Environmental
    • Noisy surroundings
    • Non-hands free environment
  • Other
    • e.g. Not operating in the users natural language
impact on system design
Impact on System Design
  • Problem: Encountered when sites are:
    • Mainly text-based
    • Mainly graphics-based
    • Provide information in purely audible format
    • Rely on certain hardware usage
    • Rely on up-to-date technology
    • Have fixed text and colour schemes
impact on system design15
Impact on System Design
  • Solution:


access technologies
Access Technologies
  • Alternative methods of system input/output
    • Screen magnifiers
    • Screen readers/Speech synthesizers
    • Braille devices
    • Alternative keyboards
    • Speech recognition software
  • Work with these when designing user interface & content
design guidelines17
Design Guidelines
  • Main Aims
    • Highlight different user contexts
    • Show alternative ways of expressing content
    • Ensure graceful transformation
    • Show ways to increase ease of navigation and understanding
design guidelines taken from w3c
Design Guidelines (taken from W3C)
  • ‘Provide alternatives to auditory & visual content’
  • ‘Don’t rely on colour’
  • ‘Use mark-up & style sheets & do so properly’
  • ‘Clarify natural language usage’
  • ‘Create tables that transform gracefully’
  • ‘Ensure that pages featuring new technologies transform gracefully’
  • ‘Ensure control of time sensitive content changes’
provide alternatives to auditory visual content
Provide alternatives to auditory & visual content
  • Serve same purpose as original format
    • Textual descriptions of images and navigation buttons/ charts and diagrams
    • Textual descriptions of auditory content
    • Non-textual equivalents
design guidelines taken from w3c20
Design Guidelines (taken from W3C)
  • ‘Provide alternatives to auditory & visual content’
  • ‘Don’t rely on colour’
  • ‘Use mark-up & style sheets & do so properly’
  • ‘Clarify natural language usage’
  • ‘Create tables that transform gracefully’
  • ‘Ensure that pages featuring new technologies transform gracefully’
  • ‘Ensure control of time sensitive content changes’
ensure control of time sensitive content changes



Auto-updating content

Ensure control of time sensitive content changes
ensure control of time sensitive content changes22



Auto-updating content


Hard to read/interact with

As yet user agents do not provide control mechanisms for this kind of feature

Ensure control of time sensitive content changes
design guidelines taken from w3c23
Design Guidelines (taken from W3C)
  • ‘Provide alternatives to auditory & visual content’
  • ‘Don’t rely on colour’
  • ‘Use mark-up & style sheets & do so properly’
  • ‘Clarify natural language usage’
  • ‘Create tables that transform gracefully’
  • ‘Ensure that pages featuring new technologies transform gracefully’
  • ‘Ensure control of time sensitive content changes’
design guidelines taken from w3c24
Design Guidelines (taken from W3C)
  • Ensure direct accessibility of embedded user interfaces
  • Design for device independance
  • Use interim solutions
  • Use W3C technologies & guidelines
  • Provide context & orientation information
  • Provide clear navigation mechanisms
  • Ensure documents are clear & simple
design guidelines25
Design Guidelines
  • Main points
    • Provide alternative ways of expressing information
    • Do not rely on any one format/ technology
    • Work with existing access technology
    • Make everything as clear and simple as possible
issues tradeoffs
Issues & Tradeoffs
  • Trade offs of guideline compliance
    • 3) Sacrifice flexibility of mark up language
    • 6) Limitations on use of new technologies
    • 11) Non-W3C technology = PDF
    • 14) Increased standardisation of web = decreased innovation and design
issues tradeoffs27
Issues & Tradeoffs
  • Issues
    • 7) and 10) Responsibility Issues
    • If many alternatives are provided, all must be updated
    • Can be time consuming and costly to implement accessibility
      • More costly to add to an existing site than develop in from start
    • Improved visitor experience
    • Increased Customer Base
  • Website Assessment
    • Lynx
    • Booby
  • Accessibility helpers
tesco com
  • First link on a text browser is to Tesco Access
  • Text-based site for slow connections, old browsers and people with accessibility issues
  • Fully opened by lynx, very few issues with bobby
news bbc co uk
  • Another site with a text-only link at the top
  • Also has a ‘skip to main content’ link
    • Lessens problems with visual impairments and the browsing paradigm
  • Allows non-sited people to view news as well as sited people
  • BBC also has Betsie
    • BBC Education Text to Speech Internet Enhancer
    • Turns any browser into a hi-visibility, customisable, text-only browser
    • BBC sites optimised for betsie
    • Changeable font, size, colours and so on.
    • Screen reader enhancements
panasonic mycinema@home
Panasonic myCinema@home
  • Very good looking site
  • Absolutely NOTHING for text-only browser
    • Not even ‘this site will not work without internet explorer’
    • Very poor page – visually impaired user wouldn’t know if it had simply not finished loading or was broken
  • Other pages have long, standard header
    • 16 pages of header on lynx before any detail
    • User not sure whether or not the page has moved on from the last one.
denon co uk
  • Site inaccessible due to imagemap
    • Text-only browser can open frames with some success
    • However the main links are contained within an imagemap with no alternative text
    • Site written by a German company, so all errors (site does not support frames, 404 and so on) are in German
things to remember
Things to remember
  • Text-only pages
  • Check site with bobby and a text-only browser
  • Alternative text for images
  • Even if your product is unsuitable for a visually impaired person (DVDs, books), they might be buying for someone else
  • If in doubt seek outside help
  • Accessibility products often use MS standards to determine what is on the screen of an application
  • Problems arise with incompatibility
    • Lotus notes compared to outlook
  • Ensure compatibility with Microsoft to help ease of use for a disabled person.
accessibility products
Accessibility Products
  • Several products available to help disabled people access the web better
    • Screen readers
    • Braille Displays
    • Magnifying and high-contrast tools for those with low site
  • These all help, but only if a website/product allows it
braille displays
Braille Displays
  • Allow blind people to read what is on screen
  • Hundreds of ‘pins’ rise and fall to represent what is on-screen in the form of braille
  • Not cheap – typical setup costs in the region of £10,000
dictation software
Dictation Software
  • Works by turning the text on-screen into synthesized voice
  • Needs no special hardware – simply a soundcard and a speaker/microphone
  • User can control the pc with verbal commands
  • Needs ‘training’ in order to work well
  • Several packages available at a reasonably low price – from £50
conceptual model
Conceptual model
  • Web is based on browse and explore conceptual model
  • This model is based on sight
  • Blind people will never be able to use the net as quickly as full-sighted people
  • Other models are more suited to lesser-sighted people – for instance command model
  • Web helps disabled people to achieve independence
  • Accessibility is important
  • Lots of design guidelines and help available
  • Keep all prospective users in mind
  • Some high-profile websites and software packages still have poor accessibility
  • Some products available to help
  • Sites we used included:
    • W3C (World Wide Web Consortium)
      • (
    • Irish National Disability Authority
      • (
    • RNIB (Royal National Institute of the Blind)
      • (
    • Web Accessibility Initiative
      • (
    • IBM able website
      • (
    • Lynx Text-Based web browser
      • (
    • Bobby webpage layout validator
      • (
    • Betsie Website->text only translator
      • (