Transcript Web accessibility for developers

Web accessibility
A practical introduction
A working definition…
“
Web accessibility is about designing
sites so as many people as possible
can access and interact with them
effectively and easily
“
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Why is it an issue?
 Lack of standards in the early days of the web
 Ignorance of the needs of disabled web users
 Development tools were very poor at creating
accessible websites
 Limited advice and support available
… Fortunately this has started to change
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Key Benefits
Reach a wider audience – up to 10 percent
Makes your site more useable for everyone (35% better)
Reduces site maintenance – lower bandwidth and hosting cost
Device/platform independence (estimated 1 in 3 devices handheld by 2010)
Improves search engine rankings
Provide Social responsibility and achieve better reputation
Future-proofing your online presence.
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Disability Discrimination Act
(DDA)
 The DDA covers employment and the provision of
goods and services to disabled people
 The DDA has been rolled out in stages to give
organisations time to adjust – grey areas
clarified by case law
 An accessible Website is given as an example of a
‘reasonable adjustment’ in the goods and services
DDA code of practice – law since 1999
 A service that is only available over the web is
arguably most at risk from this legislation;
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Issues with disabilities
The groups that have specific Issues with web and intranet accessibility are:
 Vision – including blindness, colour blindness and tunnel vision
 Hearing – both total deafness and hard of hearing
 Mobility problems with hands and arms
 Cognitive, Mental and learning disabilities
~ Many have more than one disability
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Access technology - Vision
As a very visual medium, the Web presents unique
problems to the millions who have low, restricted or
no vision.
There are 4 broad categories of vision impairment:
 Colour blindness – red/green impairment most common, affects
5% of male population and 1% female – test at vischeck.com
 Mild vision impairment – larger font size, different background
 Moderate vision impairment – screen magnification software
 Blind/severe vision impairment – screen readers
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Mild vision impairments –
Adjust the Browser
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Enabling Technology
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Assistive technology - Vision
 Screen readers are used for non-visual access to Window
applications and the Web. A screen reader allows users who are
blind to hear what is happening on their computer by converting
the screen display to digitised speech.
 Window-Eyes and JAWS are examples of screen readers.
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Hand/arm Adaptive technology
People with mobility impairments face challenges when
navigating and interacting with web pages.
They may experience difficulty moving the cursor with the
required precision or may lack the manual dexterity or hand-eye
co-ordination required to use a standard keyboard or mouse.
Some people will use voice recognition
to navigate and interact with web pages.
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Assistive Technology
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Alternative Pointing Devices
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Alternative keyboards
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Hearing
Hearing impaired people have particular problems
with inaccessible multimedia, including video and
audio clips on the web, which lack captioning and
transcripts.
Additionally for those whose first language is BSL
(British Sign Language) there are words in English
that do not exist in their vocabulary.
For example recent research by the BBC found
terms such as ‘marinade’ in their recipe section were not
understood by BSL users, highlighting the need to provide
a glossary for key words.
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Guidance for Managers
Web Content Accessibility Guidelines (WCAG) 1.0
Guidelines created in 1999 to explain how to make websites and
intranets accessible to people with disabilities.
They are prioritised into three levels:
Priority Level 1 - 'Must' or level ‘A’
Minimum - key issues: images, language, Multimedia
Priority Level 2 - 'Should', or level ‘Double-A’
Good practice - key issues: layout, hypertext, forms
Priority Level 3 - 'Ought' or level ‘Triple-A’
Beyond best practice
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Web accessibility audits
Accessibility audits have three steps:
Step 1: Compatibility testing with various
browsers.
•
•
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•
Toggle images
Toggle sound
Test Font size
Observe Color Contrast
Use Tab Control
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Web accessibility audits
Step 2: Automated testing
• Using tools such as WebXact & “Cynthia
Says”
• Requires interpretation
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Web accessibility audits
Step 3: Manual accessibility evaluation
• Most time consuming
• Most critical
• Manually test accessibility based on
guidelines:
– W3C WAI Web Content Accessibility Guidelines,
WCAG 1.0;
– RNIB “See it Right” Accessible Website
Guidelines;
– ISO/AWI 16071 “Ergonomics of human-system
interaction -- Guidance on software accessibility”
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Planning for an accessible
Website
 Obtain top management and trustee commitment
make them aware there is a legal requirement to
make your site accessible under the DDA
 Find out how accessible your site is now
 Decide on what level of accessibility you want to achieve –
W3C WCAG level 2 is increasingly becoming a goal of many
organisations
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Planning for an accessible
Website
 Create an internal team to identify accessibility
objectives - this might just be you!
 Make sure the relevant people in your organisation understand
about accessibility
 Create an accessibility policy…
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Web accessibility policy
 If any part of your website has specific
accessibility issues that will impact on the ability of
disabled people to use your site. You must document
the problem and explain how you are working
towards fixing it, and if possible give a time frame for this solution.
 For those services that are inaccessible you need to explain how
disabled people can access this information or these services via
alternative means
 Encourage feedback from disabled people
 Put a summary of your policy on your Website
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Accessibility issues for editors
Below are some key areas to consider when writing
content for the web:
 Use the simplest and clearest language appropriate for a site’s
content.
 Use short line lengths and paragraphs.
 Use pictures and symbols in addition to text.
 Provide a text equivalent for each non-text element / ensure
pictures have descriptive text
(alt attributes).
Avoid putting ‘too much’ information on a page - as a guide don’t
have more than three pages worth of content as you scroll down.
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