Disabilities and technologies (2005)

Roger Hudson, October 2005

By some estimates over 80% of the disabilities experienced by people in our communities are invisible to the wider population; so it is not surprising most website developers and proprietors believe that very few, if any, people with disabilities use the Web.

Even in terms of the more profound and obvious disabilities, such as blindness or cerebral palsy, very few web developers have had the benefit of seeing how the different assistive technologies enable people with these disabilities to use accessible websites.

Two of the most common questions I get asked are: How many people have disabilities? And, what sort of technologies do people with disabilities use to access the Web?

In this article I hope to throw a little light on these questions.

How Many People are Disabled?

The diversity of the human population encompasses a vast range of physical, sensory and intellectual differences. Use of the label “disability” always causes me some uneasiness, largely because it suggests the overarching removal of an “ability”. There are many people, myself included, who may have a condition that could be categorised as a disability, but who do not consider themselves disabled. A significant proportion of the deaf community, for example, do not see themselves as disabled in terms of hearing, but as active members of a distinct cultural group with its own traditions, choices and languages.

This said, I do use the words disability and disabilities. They are convenient labels for discussion about ways to improve websites so that they can be used effectively by people with a range of visual, aural, physical and intellectual abilities, including those with impairments in one or more of these abilities.

Trying to determine how many people have different disabilities in a society can be difficult. For a start, there is considerable variability in the way information about the incidence of different disabilities is collected. It appears to me, that it often relies on self-reporting by the person with the disability or their carer, rather an objective collection of the data by an independent person. Also, the level of impairment that determines the criteria for whether a person is considered to be disabled varies from country to country, and in some cases within a country.

Not withstanding these difficulties, it is pretty safe to say that somewhere between 10% and 20% of the population of a developed country like Australia has a disability that will affect their ability to use the Web. The proportion of the population with a disability appears to be increasing, due mainly to the aging population profile of these countries.

The incidence of disabilities (and limiting illness) that restricts a person’s ability to function in everyday life, as recorded by government agencies in some countries:

  • United Kingdom, 18% of the population (National Statistics, 2001).
  • Australia, 17% of the population (Australian Bureau of Statistics, 2003).
  • United States, 19.3% of the population (US Census Bureau, 2000).
  • Canada, 12.1% of the population (Statistics Canada, 2001).
  • New Zealand, 20% of the population (Statistics New Zealand, 2001).
  • European Union, across the 15 EU countries in 2001, 19.3% of the population was hampered by physical or mental health problem, illness or disability, with 9.3% severely hampered. (Eurostat, 2003)

Survey of Disability in Australia

The Australia-wide “Survey of Disability, Ageing and Carers” (SDAC) conducted by the Australian Bureau of Statistics (ABS) in 1998 found that 20.1% of Australians had a disability. The results of the next SDAC survey in 2003 were very similar, with 20% of the population, or 3.95 million Australians, reporting a disability. The ABS survey defined disability as:

“Any limitation, restriction or impairment, which lasted, or is likely to last for at least six months and restricts everyday activities. Examples range from hearing loss which requires the use of a hearing aid, to difficulty dressing due to arthritis, to advanced dementia requiring constant help and supervision.”

Disability, Ageing and Carers Survey (2003): Summary of Findings (PDF)

In both the 1998 and 2003 surveys, about 17% of the population had disabilities, which resulted in restrictions in one or more core activities, such as self-care, mobility and communication, or restrictions in schooling or employment. And, about 3% reported disabilities without any specific limitations or restrictions. 10% of people in Australia use equipment or an aid to help them cope with their condition or manage with their everyday life.

The people with disabilities in the 1998 SDAC were asked to indicate which disability most affected their daily lives.

Survey of People Reporting a Disability
Percent with disability
Sight 34%
Physical 20%
Hearing 11%
Speech 3%
Intellectual 4%
Psychiatric 5%
Acquired Brain Damage 5%
(or undisclosed, or multiple)

The SDAC also reported the disability rates for people of different ages in the population: Less than 4% of children between 0 – 4 years had a disability; for people 35 – 39 years the rate is about 15%; for those 65-69 the rate has increased to about 40%; the rate then increases rapidly to more than 90% for people 90 and over. In general, the disability rates for males and females is very similar, although women over the age of 80 have a much higher rate of profound or severe disabilities than men of the same age.

US snapshot for comparison.

US Census 2000 reported 49.7 million Americans over the age of 5 (19.3% of the population) with a long-lasting illness or disability.

  • 6.3% with sensory disability involving hearing or sight.
  • 8.2% with a condition limiting basic physical activity (eg walking, lifting).
  • 4.8% with a condition causing difficulty in learning, remembering or concentrating.

21.3 million people over the age of 16 (11.9%) had a condition that affected their ability to work.

US Census Bureau, “Disability Status: 2000”. Issued 2003. (PDF)

Students with disabilities

Research by Jaye Johnson from Edith Cowan University in Western Australia provides a useful insight into the incidence of disability among young people in the community.

Within the secondary education sector, there had been an increase in the proportion of the student population with a disability during the period 1997 – 1999. For example, the percentage of students in Year 12 (17 -18 years old) with a disability increased from 1.62% to 2.11% over the three years.

The proportion of students with different types of disability did not change significantly during the three-year period.

Percentage of Year 12 students with different categories of disabilities in 1999
Percent with disability
Intellectual disability 56%
Physical disability 17%
Hearing loss 14%
Visaul loss 9%
Autism 3%
Language disability 1%

Within the post-secondary sector, Universities and TAFE (Technical and Further Education) colleges in Western Australia provided statistics relating to students with disabilities. The proportion of students with disabilities in TAFE colleges was between 1.32% and 3.63% and in Universities between 0.7% and 3.0%. (Johnson felt the 0.7% figure resulted from a data collection issue and was not an accurate reflection of the population).

There were significant differences in the reported types of disabilities. In TAFE, 27% of the students with disabilities had a physical disability followed by 22% with vision impairment. Whereas, in Universities 39% of disabilities resulted from a medical condition and only 9% identified having a physical disability and 9% with vision impairment.

“Indicators in the secondary, post secondary and ABS data suggests that there will be an increasing number of people with a disability over the next 8 – 10 years who may access post secondary education and training. Of these students, it is likely a greater proportion will have severe to profound levels of disability than is seen in the present student population.”

Jaye Johnson, “Students with Disabilities in Post Secondary Education. Issues and Trends For a New Decade”.

Research by the Australian Learning Disabilities Association found, “The incidence of learning disability in Australia, as in other western countries, is suggested to be 10% to 12% of the population, with 4% being severely affected”. Source: What is learning disability?

Assistive Technologies

An assistive technology device, as defined by the United States Assistive Technology Act of 1998 , is any “product, device, or equipment, whether acquired commercially, modified or customized, that is used to maintain, increase, or improve the functional capabilities of individuals with disabilities.”

There is a wide range of computer-related assistive technologies (also called adaptive technologies) that can help disabled people access information that may otherwise be inaccessible to them because of their disability. A short description of some of these technologies follows, for convenience they are categorised as input or output technologies.

Input Technologies

An input technology is a device that allows the user to enter information into a computer. Most people use a standard computer keyboard and mouse to access the Internet and surf the Web. Not everyone however, can use both these devices, for example the mouse, which requires the user being able to see the cursor on the screen, is of little use to many vision-impaired web users who mostly use the keyboard to access the Web.

Thankfully, for people who are unable to use a standard keyboard and/or mouse, other input technologies are available.

Alternative keyboards

There are a variety of alternative physical keyboards. For example, there are ergonomic keyboards for people who have hand and upper limb injuries, keyboards that present the keys in a different order (ABC rather than the conventional QWERTY), keyboards that use large keys and colour coding of the letters for people with cognitive and/or vision impairment and keyguards that can be used to reduce the risk of the wrong key being activated. Also, the layout of some keyboards can be extensively customised to meet the specific needs of individual users.

Onscreen virtual keyboards

Some people are unable to type, perhaps due to impaired mobility, but still require the functionality provided by a keyboard. Specialist accessibility software can be used to display a virtual keyboard on the computer screen that allows users to enter data with a standard mouse, pointing device or joystick. Onscreen virtual keyboards can also help people who do not know how to type.

Alternative mouse systems

The standard mouse can be difficult for people with some disabilities to use. The user needs to be able to see the mouse cursor, and then move the cursor on the screen by moving the mouse across a flat surface in a precise way. The trackball and touchpad are probably the two most widely used alternatives to a standard mouse by people who are able to see the screen, but who have impaired upper-limb mobility.

A trackball is like an upside-down mouse, with the ball on the top and often with several buttons, much like an advanced multi-button mouse. With a trackball the actual device remains stationary and movement or rotation of the ball moves the cursor. Different sized balls can be used and people with significant fine motor skill problems often use a large ball. The ball is usually moved with the hand, but can also be operated with the foot, elbow or a stick held in the mouth.

A touchpad allows the user to move the cursor on the screen by moving a finger across the touchpad surface, as occurs with many laptop computers. Touchpads can be used by people who are unable to hold a device such as a standard mouse or who have very limited mobility, perhaps an ability to move just one or two fingers as may be the case when someone has motor neurone disease.

Some alternative keyboards can also function as a mouse through the use of Mousekeys. Both Windows and Apple operating systems for example, incorporate Mousekeys as an accessibility feature for people who have difficulty using a mouse. MouseKeys allows the user to control the movement of the mouse cursor with the numeric keypad.

Head wands

A Head wand is a simple device that is strapped the users head, and has a protruding stick that is used to type keys on a standard or modified keyboard. People with severely impaired limb mobility, but who are still able to move their head (for example, someone with cerebral palsy) are able to effectively use websites with head wands.

Head wands are often used in conjunction with the StickyKeys accessibility option that is available with both Windows and Apple systems. Keyboard functions that require the simultaneous pressing of two (or more) keys can be done with StickyKeys, since it enables the user to press a key and release it, and then press the other key or keys, and the software acts as though the keys are being pressed simultaneously.


People with very limited mobility maybe unable to use either a modified keyboard or mouse. A range of adaptive switches is available to help people in this situation use a computer and access the Web. Most switches consist of one (or a few) buttons, which can be activated by bodily movement. For example, a person who can only move their head maybe able to surf the Web by clicking a switch embedded in a headrest, while someone else might require a foot switch.

Other switches are touch free, relying instead on motion sensors, brain activation, or a suck and puff mechanism.

Switches are often combined with specialist software that extends the functionality of the device allowing more complex tasks to be undertaken. For example, auto-complete typing software can reduce the amount of typing required by looking at what the user starts to type and then presenting a range of choices that the user can select from to complete the word or phrase.

Voice (speech) recognition

Voice (or speech) recognition software allows a person to control a computer with their voice. With voice as the input device, speech can be used to open programs, write documents, save work, use the Web and write and send emails. There is a wide variation in the way people speak, so the voice recognition software needs to learn how to recognise the user’s voice and the way they pronounce words. It can also remember commonly used phrases and words and use this information to make predications about what is to be input, thereby speeding up the process.

The accuracy of voice recognition has improved significantly in the last few years however, they still require the user to speak in a voice that is relatively easy to understand. People with disabilities that affect their ability to speak (for example cerebral palsy) may have difficulty using voice recognition as an input technology at this time.

Eye tracking

Eye tracking software allows people to use a computer with nothing more than eye movements. People with little or no control over the movement of their hands, and who also may not be able to speak, can use eye-tracking systems to operate a computer and access the Internet. Some eye tracking software can be combined with a virtual keyboard allowing the user to type by moving their eyes.

Eye tracking systems have the potential to bring very significant benefits to a relatively small number of people. However, at this stage they are very expensive and not widely used as an assistive technology.

Output Technologies

An output technology is a device that presents the data or information from a computer to the user. Most web users are familiar with commonly used output devices such as computer monitors and screens, speakers, printers and projectors. Mobile phones, PDAs, plotters and film recorders can also be used to output website content.

A number of specialised assistive output technologies are available to enable people with disabilities to obtain information via the Web.

Screen readers and talking browsers

Screen readers and talking browsers interpret information that can be visually displayed on a computer screen and then present this information as audio output by synthetic speech and/or as tactile output by Braille display. Screen readers and talking browsers also interpret the input interactions made by the user, for example keyboard strokes, entering search requests and checking form radio buttons. These technologies are widely used by people with little or no vision. They are relatively difficult to learn and use and are usually controlled via a standard computer keyboard.

Screen readers don’t read the screen. Working in conjunction with a web browser (usually Microsoft Internet Explorer) and an Application Programming Interface (eg. Microsoft Active Accessibility) screen readers use the source code of a web page to construct an alternative, accessible representation of the page and the functional components it contains. When a page is coded correctly, most screen readers are able to present (either through speech or Braille) the text on a web page, alternative descriptions for images and multimedia content, as well as identifying headings, lists items, links, frames, tables and form elements.

The most widely used screen readers in Australia are JAWS (available from Freedom Scientific) and Window-Eyes (GW-Micro). HAL and Supernova (Dolphin Computer Access) and LookOut (Choice Technology) are also used in Australia, but more widely used in other countries, particularly in Europe. Recent versions of the Windows and Apple operating systems have built-in screen readers, but the features are limited so they are not widely used by people who depend on a screen reader to access the Web.

Talking browsers are specialised Internet browsers that are able to present the content of a web page as speech in a similar way to a screen reader. IBM Home Page Reader is the most widely used talking browser. The Home Page Reader speaks web-based information as it is presented on the computer screen and allows the user to identify the different elements of the page such as headings and links. Users with low vision can use the Home Page Reader to magnify the screen and change font size and colour.

Braille display

A Braille display is a device that allows a blind person to read the contents of a computer display (or website) as a line of Braille characters. Braille display devices that are used with computers and the Web are often referred to as Refreshable Braille Displays, since the line of Braille characters refreshes as the user moves from one line to the next.

Refreshable Braille devices have a strip of rubberised material under which is a row of pins that can be made to rise and fall by electrical signals. The pins are presented in groups (arrays) of six or eight pins, which when activated form a Braille character, similar to the raised dots of Braille impressed on paper. There are usually 40, 65, or 80 arrays (characters) per line of text, depending on the size and cost of the device. Refreshable Braille displays generally include directional keys, which allow the user to navigate through a document.

When used in conjunction with a keyboard, the Refreshable Braille display enables a person to operate a computer, read text, send and receive e-mail, and browse the Web.

Refreshable Braille display devices are considerable more expensive than screen reading software to purchase and are less commonly used for accessing the Web when compared to screen readers. However, Braille is an essential communication medium for people with impaired vision and hearing.

Screen magnifiers

Screen magnifiers allow people with low vision to access information on a computer screen. The magnification software can increase the size of the information by a pre-determined amount. Most programs offer a maximum magnification of 16 times, but the most commonly used level of magnification appears to be 4 or 6 times magnified.

The screen magnifier increases the size of everything displayed on the screen, not just the text. Web pages that most people can view without scrolling require scrolling when viewed with a screen magnifier since only a section of the page will fit onto the computer screen. The mouse or keyboard is used to scroll vertically and horizontally as the users moves the area displayed in order to see all the content of the page.

Most screen magnification software has the flexibility to magnify the full screen or parts of the screen. These programs also often allow for inverted colours, enhanced pointer viewing and tracking options. Many screen magnifiers also contain screen reading software that can be used to speak the page content if the user wishes.

The most widely used screen magnifiers in Australia and elsewhere include, ZoomText Magnifier (developed by Ai Squared), MAGic Screen Magnifier (Freedom Scientific) and Luna and Supernova (Dolphin Computer Access).


All of the output technologies considered thus far are primarily concerned with improving the ability of people with impaired vision to access information presented with text or static images. The web however is increasingly becoming a multimedia environment containing video and audio material. Unfortunately, progress in improving the accessibility of this material is slow.

I am not sure if you can describe captioning as an output device, however it is a technique that will allow people with impaired hearing to read a description of audio content. Captions describing visual content can also be rendered by screen reading technologies thereby allowing people who can’t see the content to access the information presented.

Joe Clark, one of the pioneers of captioning, provides a good overview of the issue and captioning techniques in his article, “Best Practices in Online Captioning”.

Jared Smith from WebAIM presented a paper on the subject at the “Technology and Persons with Disabilities Conference 2004”, which also highlighted the need to provide captions for audio web content.

“On the Web, synchronized, equivalent captions should be provided any time audio content is presented. This obviously pertains to the use of audio and video that is played through multimedia players such as Quicktime, RealPlayer, or Windows Media Player, but can also pertain to such technologies as Flash, Shockwave, or Java when audio content is a part of the multimedia presentation.”

Jared Smith, “Captioning Web Multimedia: An Overview of Technologies, Resources, and Tools”.

Device Independence

Many different devices are now being used to access the Web. In addition to the examples of assistive technologies described above, people are accessing the Web with an increasing range of devices including mobile (cell) phones, WebTV, PDAs, Kiosks, and not forgetting of course, the Internet fridge.

The number of web browsers available is also increasing all the time. The Evolt Browser Archive contains over 100 browsers including, the original World Wide Web (NeXus) browser developed by Tim Berners-Lee, text-only browsers like Lynx, Microsoft Internet Explorer (different versions) and the hot new favourite, Firefox.

Ideally, all the components of a website should be able to be accessed by any device or user agent that a web user might wish, or is required, to use. Although this is an ambitious, and some might say unrealistic aim, the W3C Web Accessibility Initiative sees device independence as a key component of web content accessibility.

“Users must be able to interact with a user agent (and the document it renders) using the supported input and output devices of their choice and according to their needs. Input devices may include pointing devices, keyboards, Braille devices, head wands, microphones, and others. Output devices may include monitors, speech synthesizers, and Braille devices.

Please note that “device-independent support” does not mean that user agents must support every input or output device. User agents should offer redundant input and output mechanisms for those devices that are supported. For example, if a user agent supports keyboard and mouse input, users should be able to interact with all features using either the keyboard or the mouse.”

Web Content Accessibility Guideline 1.0

HTML is the original language of the Web, and for a while HTML was the only way information could be made available via the Web. HTML, and its successors, use standards that have been developed by the World Wide Web Consortium (W3C). Today however, in addition to material developed using the standards and formats recognised by the W3C, many websites present content in a variety of other formats, with varying degrees of accessibility.

A lot of words have been written and spoken about the terms accessibility, availability, compatibility and interoperability, with the aim of defining, differentiating and explaining their meanings. Also, there is hot debate about where responsibility lies for making sure all web users, including those with disabilities, can access material on websites. Unfortunately this discussion sometimes swirls around in an esoteric whirlpool.

Clearly, developing a site using only recognised W3C standards and formats will maximise its potential to operate with standard compliant browsers and a wide range of input and output technologies. However, this is not always possible or even desirable. For example, the use of a non-W3C format Flash animation, will in some cases improve the usability and even accessibility of a site for some users.

In recent years, the manufacturers of two commonly used non-W3C formats, PDF and Flash, have significantly improved the accessibility features of their product. It is now possible to develop PDF or Flash material, which can be accessed by a wide range of assistive technologies. Unfortunately however, not all web developers have the knowledge, skill or commitment to ensure the material they develop using these formats is accessible. Also, earlier versions of many assistive technologies such as screen readers, which are still widely used, do not support the recent accessibility enhancements.

Another concern is the ability of different assistive technologies or technology versions to recognise and interpret valid web page code. Many screen reader versions for example, do not recognise all the standard W3C coding options that are available to improve the accessibility of data tables.

Who is responsible for ensuring the content on a website can be accessed by people with disabilities who rely on different devices? Clearly the developer has an important role to play. However as indicated earlier, it is possible to use non-W3C format material in a way that can be accessed by recent versions of some assistive technologies; and, some W3C standards material does not work with some technologies.

Of course, as a site developer you could say, “I have done all I can, and it is up to the vendors of assistive technologies to improve their product and the users of these technologies to obtain the most recent version of these products”.

While this attitude might provide you with some moral comfort and put a little pressure on assistive technology manufacturers, it does little for the person with a disability, who is using a technology that enables them to adequately use most other sites, but not your site or the site of your client.

I take a pragmatic approach to the issue of accessibility. In my view, website content should be able to be accessed and used by the widest possible range of people using the software and hardware, particularly assistive technologies, that are in general use at the time. This means developers should:

  • Use recognised W3C specifications and standards appropriately.
  • With scripts and applets, avoid the use of device-dependent event handlers such as onMouseOver. If mouse dependent event handlers are used provide keyboard handlers such as onFocus as well.
  • Wherever possible avoid the use of non-W3C formats. And when they are required, use a recent version of the authoring program and the accessibility features provided.
  • Provide alternative access to information contained in non-W3C format material, ideally in the form of a standard HTML version of the content.
  • Check the website material to make sure it can be accessed and used by people who rely on assistive technologies that are in current use.

It sometimes seems that the wish of people like Tim Berners-Lee and Chuck Letourneau for a universal Web, which can be accessed by anyone, anywhere, using any web browsing technology, is a forlorn hope. But it isn’t!

More and more people are working to make the Web a universal medium with content that can be used by people worldwide with different abilities and technologies.

References and more information

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