A user-centred approach to web accessibility
Most web developers act in blindness when they design accessible websites, since they know next to nothing about disabled people and the technology they use. Accessibility guidelines and validation tools doesn't provide this insight. Accessibility should rather be approached from a user centred perspective.
In a governmental health care project, we had both an accessibility
consultant and a blind person evaluating a website. The accessibility
expert ran the site through a systematic validation and found "6
priority 1 errors" and "8 priority 2 errors." This gave
the site the lowest evaluation possible: "A bad website in terms
of accessibility." Our blind accessibility tester evaluated the
site with his screen reader and was fairly pleased. He praised the site
for being well-structured and didn't find any severe accessibility problems,
though he had problems here and there. While the outcomes of the two
tests were disturbingly different, it was even more disturbing that
most of the problems that the blind tester found didn't attract the
attention of the accessibility consultant.
There may be many explanations to the different
results. One is that meeting the letter of accessibility requirements
might not be the most important thing when designing web sites, which
are well-functioning for people with disabilities.
The potential of accessibility
The Internet is a gift from above to people all over the world. For disabled
people, the potential of the Internet is particularly remarkable. It
opens a whole new world of opportunity and independence to them.
Disabled people are able to access websites using
inventive assistive devices, which help them overcome their disabilities.
This includes sites, which don't comply with the official accessibility
requirements. But badly designed web sites can make it quite tedious
- and in the worst cases impossible - for disabled people to access
With a little thought, web developers can improve
the online life of disabled people remarkable. Adding text alternatives
to images make the world in difference. Imagine a blind person using
a screen reader having to listen to all the file names of the images
with no text alternative:
right underscore corner dot gif graphic spacer dot gif graphic left
underscore corner dot gif welcome to john smith's website graphic pict
5 9 4 9 3 0 8 5 dot jpeg graphic spacer dot gif...
Adding text alternatives to pictures and leaving
them blank for images used solely for visual design, the page would
read like this:
to john smith's web site graphic picture of me eating a hotdog...
Much more comprehensible.
Since most web developers have no idea of how disabled people
experience websites, they grope in the dark when trying to design accessible
web sites. Knowing nothing about disabled people and the tools they
use, they lack two of the most vital prerequisites of good design: knowledge
of the media and knowledge of the audience.
Most developers resort to official accessibility
guidelines such as the World Wide Web Consortium's (W3C)
Web Content Accessibility Guidelines (WCAG),
and relies on validation tools, such as Bobby.
The rationale is that "If I follow these guidelines and Bobby is
happy with me, this site will be usable for disabled people" -
or just "…then I got my arse covered."
While guidelines and validation tools can be very
useful tools, they cannot replace human expertise. In spite of all good
intentions, guidelines are by nature vague and require interpretation
and testing when put into practice.
Even if you adhere to the accessibility guidelines,
you can still screw things up. Recall our previous screen reader example.
If John Smith chose to meet the letter of the WCAG Guideline 1, which
tells him to add text alternatives to all images, we could end up with
something like this:
left blue corner graphic blue spacer used to add white space graphic
right blue corner welcome to john smith's website graphic picture of
me eating hotdog...
Fortunately, most web developers know that they
should leave a text alternative blank, if the image is used solely for
Disabilities and their accommodations
There is no way we can make disabled peoples experience of the
web equivalent to that of non-disabled people. What we can do is to
make it less tedious within their particular field of experience.
Some disabilities are quite simple to accommodate.
Since the web is mostly a visual media, the obstacles of deaf and hard-of-hearing
are minor. Other disabilities are, in practice, impossible to accommodate.
For people with learning disabilities reading is the biggest problem,
and there is no proven way to make textual websites accessible to people
who cannot read well.
And then there are technological "disabilities",
which people using antique hardware or mobile phones with tiny screens
suffer from. Some purists will claim that accessibility counts for everybody
in any imaginative situation. But technological "impairments"
are in most cases self-imposed and can be changed - severe physical
impairments can't. Designing a good-looking web site, which is truly
universally accessible for all kinds of inventive devices, is almost
The disability groups that we can and should accommodate
are colour blind people, mobility impaired people, people with low vision,
and blind people. Unfortunately, it's outside the scope of this article
to present you to the ways that these disability groups experience the
web and how to accommodate them. Fortunately, others have already done
that. I can strongly recommend you to read Joe Clark's book, Building
Accessible Websites, which will give you a head start. He explains
web accessibility in a very engaging way and has tips on how to make
websites accessible on basic, intermediate, and advanced levels. If
you want more, read Mark Pilgrim's Dive
Into Accessibility. His book starts out with a gallery of fictitious
disabled internet users, which will give you an idea of how disabled
people experience the web. Both books are available online.
Designing and testing accessibility
Designing websites for disabled people is essentially no different
from designing websites for non-disabled people. It requires knowledge
of technological possibilities and limitations and knowledge of the
users and their needs. Without this knowledge, you are designing in
Reading books about accessibility is a good start,
just like it's a good start reading web design books when designing
for non-disable people. They provide you with a basic knowledge of the
problems that disabled people face and practical advice on how to accommodate
If you are starting from scratch, it might be tempting to hire accessibility
consultants to guide you and run screenings of your work. But be careful.
Some of them - even experts from highly estimated consultancies - will
simply throw lots of accessibility guidelines at you (including the
ones they make up themselves) and run sites through validation tools,
which are available online for free or can be bought for a fraction
of their fee. You can do that just as well yourself. Then it's better
to make contact with some experienced internet users with disabilities,
whom you can consult when needed.
If you want guarantees that a website is well-designed
for people with disabilities, you have to run usability tests with disabled
people. Some consultancies offer such tests. You can also choose to
run the tests yourself. Most disabled web users will be glad to help
you out. You can always adjust the number of tests and tests participants
to your budget and time scale. Having a single disabled user evaluate
a site is not optimal, but can still be quite an eye-opening experience.
And then we have the Web
Content Accessibility Guidelines, which will cover our arses.