How the rules help disabled people
Following the twelve simple rules, you make pages more
accessible to many people. This includes the following:
- Simple language helps people with cognitive disabilities
or with dyslexia (difficulty of reading). It is also very important to
people who do not know the language of the page well, e.g. because they
are immigrants who are just learning it.
- Descriptive link texts also help people with cognitive
disabilities. For example, difficulties in short-time memory make it
essential that links are easy to understand and to distinguish from each
other. Moreover, people with visual disabilities often use speech browsers
in “link reading” mode to get an idea of what links there are.
- Alt texts are essential to all non-visual browsing (speech
browsers and Braille browsers). They may also help people who can see
images but have problems in understanding their meaning.
- Explaining content images, too, is crucial to people with
- Avoiding auto-start helps people who easily get
disoriented by moving content. Moreover, it helps to avoid conflicts with
special software that disabled people may use. If you are using a speech
synthesizer for browsing, you do not want any background music to start
- Text transcriptions of audio clips help people who cannot
hear well enough or have difficulties in understanding the language as
spoken. Text descriptions of video clips can be used to generate a speech
presentation to people who cannot see well enough. They also help people
who have difficulties in understanding speech, gestures, etc.
- Alternatives to forms help people who find it difficult to
fill out forms e.g. due to motoric disabilities or lack of understanding
of how forms work. For example, many people have great difficulties in
presenting their question or feedback in writing but could easily present
it by phone.
- Avoiding “PDF only” or “Word only”
formats mean that the accessibility problems in these formats are avoided.
Despite progress in improving their accessibility and despite software
vendors’ claims, this is still a very important issue. When a user
follows a link to a PDF file, there will usually be a delay, a possibility
of software crash, disturbing messages about data format mismatch, etc.,
and the user interface of a PDF viewer (such as Acrobat Reader) is
different from that of a browser. These are often just an inconvenience,
but to people with disabilities, they may create serious barriers.
- Linearizability is essential in non-visual presentation.
Visual presentation may also need to be linearized, e.g. in text-only
browsers and graphic browsers working on a very small screen.
- A sufficiently large font size and the possibility of
changing the font size easily are essential to people with reduced
eyesight. People with considerable visual impairment are not affected,
since they use non-visual browsing or a visual browser that uses a
sufficiently large font size, irrespectively of settings on the page. But
people with less serious problems will keep trying to read texts despite
the difficulties. Thus, this problem is relevant to a very large group
people. When a page sets font size to very small, e.g. to 9 pixels, the problem
may affect the majority of users.
- Reasonable and adjustable width helps people with some
eyesight problems (narrow scope of vision) and people using special
devices to access web pages. It also makes it easier (often much easier)
to get a good-quality printed copy of the page, and to many people,
printed documents are easier to read than on-screen reading. Moreover,
many people have cognitive problems when they have to work with a
“wide scope.” They can physically see a wide area but they
mentally get lost in the wilderness when trying to understand its
structure and content.
- Explaining the inaccessibilities helps people to avoid
frustration. When people know about the problems, they can try to find
methods of overcoming the limitations (e.g., using a different browser or
asking for someone’s help). They can also make rational choices
between sites, e.g. between an accessible site and a more content-rich but
less accessible site about the same topic. Besides, if you can make and
keep promises about fixing the problems, the offence will be reduced and
people will know that they can return to the site later.