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ASPECTS OF WEB DESIGN
WEB SITE ACCESSIBILITY
OBJECTIVES
Suggest criteria for producing effective multimedia applications
Look particularly at Accessibility and Usability Suggest factors to be avoided when
producing multimedia applications Investigate some visual impairments through
simulation Research current literature on accessibility
and websites
ACCESSIBILITY
"The power of the web is in its universality. Access by everyone regardless of disability is an essential aspect." Tim Berners-Lee (1997) http://www.w3.org/Press/IPO-announce
WHY BOTHER! WHO CARES!
The percentage of people with disabilities in many populations is between 10% and 20%.
Not all disabilities affect access to information technologies such as the web (for instance, difficulty walking, or a heart condition, would not affect web access) but many do.
FIVE PRIMARY DISABILITIES
Visual impairments Hearing impairments Mobility impairments Intellectual Impairment Cognitive impairments Seizure disorders
7% of all men are colour blind!
INTELLECTUAL IMPAIRMENT
Historically, intellectual disability was defined through intelligent quotient (IQ) scores—0– 70 points for people with ID, compared with a general population range of 100 ± 15 points, according to the World Health Organization (WHO).
(KENNEDY et al 2011) Paper on VLE
COGNITIVE IMPAIRMENTS
Include: Down syndrome, Traumatic Brain Injury (TBI), Autism, Dementia
Also Dyslexia, Attention Deficit Disorder, Dyscalculia, and other learning disabilities.
From: http://www.disabled-world.com/disability/types/cognitive/
WHY BOTHER?
Accessibility = usability
‘It is also notable that both blind users and non-impaired users took far longer on low accessibility sites than on high accessibility sites, and that this effect was not much more pronounced for disabled users: 51% longer for blind users, and 46% for non-disabled users.
It follows that all users, not just disabled people, would benefit greatly from the measures required to make sites accessible and usable by blind people.’
WHY BOTHER? legal implications;
various pieces of legislation relating to accessibility best practice;
guidelines for accessibility overlap considerably with usability
search engine optimisation; SEO is usually a very important aspect of web design –
accessibility guidelines help search engine spiders too… ethical considerations;
do we have a moral duty to not exclude groups of users?
even if you don’t feel obligated personally, others will alter their opinion of your site if you are seen to exclude some people…
THE DISABILITY DISCRIMINATION ACT (DDA) 1995 AND 2005
gives disabled people rights in; employment education access to goods, facilities and services buying or renting land or property
requires public bodies to promote equality of opportunity;
defines ‘disabled’ as; ‘someone who has a physical or mental impairment
that has a substantial and long-term adverse effect on his or her ability to carry out normal day-to-day activities’
IMPLICATIONS OF THE ACTS websites are not addressed separately, but
included in the act under ‘services’, eg ‘What services are affected by the Act? An airline
company provides a flight reservation and booking service to the public on its website. This is a provision of a service and is subject to the act.’ (Code of Practice 2.13 - 2.1, 1999)
puts a legal obligation on the website owner to ‘make reasonable adjustments’ Section 19; Discrimination in relation to goods,
facilities and services
IMPLICATIONS OF THE ACTS a ‘failure to comply’ must be justified
Section 21; Duty of providers of services to make adjustments.
‘For the purposes of section 19, a provider of services also discriminates against a disabled person if he fails to comply with a section 21 duty imposed on him in relation to the disabled person; and he cannot show that his failure to comply with that duty is justified.’ (DDA, 1995)
affects intranets as well equality of opportunity means accessibility within an
organisation, as well as the public web site
WHAT ARE ‘REASONABLE ADJUSTMENTS’?
the act does not provide specific guidance for websites, but accepts that various factors will apply, such as; the type of service being provided the type of organisation providing the service resources available to the organisation the effect on the disabled person and likely effect on
other disabled persons …a small florist is likely to be held to a different
standard than a major airline…
WHAT ARE ‘REASONABLE ADJUSTMENTS’? to date, no case has been brought against a
website owner in the UK no case law or tort for guidance plenty of precedent for defining ‘unreasonable’ in
other areas of the law several cases elsewhere, eg hotels.com, Maguire v
SOCOG (Australia) http://www.tomw.net.au/2001/bat2001f.html
case brought against on-line examination provider; Project Management Institute details at http://www.out-law.com/page-7692 candidate passed but brought successful case for
damages anyway against US firm operating in UK
COMPLYING WITH THE LAW currently impossible to guarantee compliance due
to a lack of case law; ‘It is not possible to provide a definitive specification for a fully
accessible website which will satisfy the requirements of the DDA. Website commissioners should therefore be sceptical if contracting companies declare that they will create websites that are “DDA-compliant” or “compliant with the law”. Conversely, website commissioners should not require a web designer to design a website that is “DDA-compliant” or “compliant with the law”. Until case law has been established such claims cannot be made or honoured.’ (9.1.1 PAS 78 , 2006)
sensible option is to make sure you have a policy statement about your compliance… …and to be able to back it up with evidence that you’ve made
‘reasonable adjustments’…
PRACTICAL STEPS FOR ACCESSIBILITY probably the most concise and comprehensive
source of information is the WCAG 2.0 quick reference; http://www.w3.org/WAI/WCAG20/quickref/
‘following usability guidelines gives you 80% of accessibility guidelines’ - Steve Krug
Don’t overlook the very basics of accessibility; use clear, easy to read text – test the effect of altering the text
size in different browsers avoid absolute sizes for text areas so that the page displays in
low resolutions aim for a fluid rather than fixed layout; use percentage values
instead of absolute values
don’t use ‘access keys’ there’s no agreed ‘standard’ – different sites use
different keys they can override screen readers and make the site
even worse for those that help the most don’t bother with ‘accessibility widgets’
users’ machines will be set up to their own preferences; don’t override their browser’s settings
leave out ‘statements of compliance’ users will decide for themselves whether or not the
site is accessible whatever you say
quick and easy things to do;
QUICK AND EASY THINGS TO DO; specify the language; <html lang="en">
especially on pages with technical information avoid horizontal scrolling
this is good practice anyway, but can be very difficult for those with poor mobility
provide alt text for images that describes the image concisely like ‘photograph of Gordon Brown looking nervous’
for images used for backgrounds, list items, etc have the alt text set to “ “ so that screen readers ignore them silently (and do not
read out the file name of the image) provide summary text for tables only if context is
not clear from the rest of the page content if the text says ‘the table below shows music industry
revenue for the last five years’ there’s no need to repeat that in the table summary
quick and easy things to do;
put an invisible ‘skip links’ link at the start of your navigation list skip to the next level of navigation on a large site, or
to the main text area of the page never put in links that say ‘click here’ or similar
the link itself should describe the target don’t separate adjacent links with space –
character – space eg privacy policy - copyright - disclaimer (some old browsers needed this to help screen
readers, now it’s just a nuisance)
quick and easy things to do;
choose URIs carefully; avoid upper case, make it short but more importantly
make it descriptive make it future proof as much as you can so that
locations do not change as the site evolves consider the structure of the page
divide into logical sections so that users can skip around the page quickly - navigate by heading
summarise the content as part of the first few sentences (most screen readers can skip to the next heading with a single key - no need to listen to the whole thing)
quick and easy things to do;
FURTHER INFORMATION Webaim
http://wave.webaim.org open source screen reader
http://www.nvda-project.org/ FireVox plugin for Firefox
http://firevox.clcworld.net/ Web Developers’ Toolbar
https://addons.mozilla.org/en-US/firefox/addon/60
information from Pinsent Masons (law firm) http://www.out-law.com/page-337
advice from Google http://www.google.com/support/webmasters/bin/answer.py?answer=35769
WORKSHOP
Look at the examples of visual defect simulated with glasses
Colour Blind test Sim Dis simulation Which side of brain is dominant Research current literature on accessibility
and websites Readings on Moodle