Disabled Users, tools and techniques
How Disabled People Use The Internet
It is important for web designers, and content authors, to understand how disabled people use the Internet, so that they do not introduce barriers that prevent disabled people from benefiting from the technology.
Many disabled people use a standard web browser such as Internet Explorer or Firefox. However they may not use the browser in the same way that non-disabled people do. This is the benefit of the web's adaptability. Unlike most other media, the web allows the user to configure the output to suit their particular needs.
A common thing many people do (not just disabled) is to enlarge the font size to make the text easier to read. On most modern browsers enlarging fonts is achieved by pressing CTRL and the plus key (+). Fonts are enlarged in 10% increments. An alternative way to enlarge the fonts is to use the "View" menu, select the Text Size option and then the size of text required. The screen shot shows the Internet Explorer View Menu with the text size option selected.
Once the larger text size is selected it will stay in effect on all subsequent pages or websites until changed by the user. For this reason there should be no need for web authors to offer large print alternatives of their site. Users who need large print will already have configured their browser accordingly.
Some people find that different colour contrasts are easier to read, for example many people with dyslexia find that yellow text on a blue background stops the letters jumping around, others find that black on pink works best. Most modern browsers allow the user to over-ride the colour and font settings of a web site in order to make the content easier to read for people with some visual impairments.
Changing colour scheme with Internet Explorer
Changing colour scheme with FireFox browser
Many disabled people cannot use a mouse, either because they cannot see the cursor, or because they do not have the required hand-eye co-ordination or motor control. These people mostly use the keyboard for navigation. They can scroll up and down the page using the cursor keys, move through links using the tab key, go back to a previous page using the backspace key, close the current window using the CTRL + N keys and so on. A full list of the keyboard functions available for each browser can be found in the browser�s "Help" or "Accessibility" menu.
Because most web-designers use a mouse to help them create their websites they often build barriers for keyboard users into their sites without realising it. It is easy to check if your web site works without a mouse, just put the mouse out of reach and try to navigate around your site using the keyboard only. If you built your site using correct HTML code, and structured your pages in a logical order, then you should be able to navigate quite easily by just using the keyboard. If you do find problems it will probably be due to using external scripts or other applications and you will need to make changes to the way your site works.
Converting text to audio
Most modern computer operating systems include a facility to convert the text on the screen into audio output (speech). Special applications (plug-ins) are available for web browsers that will read websites out and highlight words as they are read out. Browsealoud (http://www.browsealoud.com/) is just one such application. The user selects the area of text and the programme reads the content out loud through a speaker. These tools are not designed for blind people (see screen readers below) but they are particularly useful for people who have difficulty in reading or have some limited vision.
For those people who cannot use a standard browser there are a number of tools available. The following are the most popular at present (2009)
The name screen reader is, in fact, a misnomer since they do not read the screen. Screen readers load the page content (the actual HTML code plus text) from the browser's document into a virtual buffer (special memory area). The user is then able to review this virtual buffer at will using selected key strokes. Items such as links, form fields, headings and other HTML elements are identified when they are read out aloud by the software. When the user finds a link or other click-able element that they wish to activate, they simply press Enter, and the screen reader tells the browser where they "clicked". There is a wide variety of options with screen readers, with users having the ability to change the rate, pitch, volume of speech output. Some use an external keypad or touch tablet to operate the reader, others use keyboard commands.
The user can set the screen reader to read the whole page as a continuous flow, or one line, one word, or even one letter at a time. To help the user orientate himself the screen reader can also read out the first 50 links on a page or a list of the section headings, providing these have been coded correctly in HTML. Keyboard shortcuts can be used to take the user to the top or bottom of the page, to return to a previous page, search for individual words on the page and a variety of other actions. Good quality screen readers are expensive (circa £600+) but can be configured in many different ways to suit the user's needs. However, blind people are just the same as the rest of us, and few read the manuals properly. As a result most blind users stick with the default settings.
An excellent video showing how a screen reader works is available from the University of Madison on Youtube :-
Refreshable Braille displays provide a line by line tactile output of information displayed on the computer monitor. This is done by means of small, rounded pins that are lifted in order to form Braille characters. The user "reads" the braille display by running a finger over the pins. Braille displays are used by people who have both visual and hearing disabilities. Because the braille display only presents one line of text at a time instructions such as "Select from the menu opposite" or "click on one of the coloured boxes below" are inaccessible! There is an excellent video showing how a blind person with hearing impairment uses a braille pad to go shopping on the Internet in Roger Hudsons web-log (see the resources section at the end of this page)
A touch screen is an electronic device placed over, or built into the monitor of the computer. It allows the user to make a direct selection of an item on the computer screen by touching the screen with a finger or a stylus. These devices are usually plugged into the mouse port of the computer. Touch screens can help focus visual attention and provide a more direct response either for early learning of cause and effect or, when used in conjunction with an on-screen keyboard is a direct way to type.
Pointing and Typing Aids
These are most often a wand or stick held in the hand, mouth; or strapped to the chin or head. Useful for individuals who have limited hand control. More advanced tools include "blow and suck" tubes and eyeball tracking devices that allow people with paralysis to work a computer. Scrolling up or down a page, or tabbing through the links on the page is fairly easy, but actions requiring finer control, such as selecting an area of an image map, is much harder and often requires more than one attempt.
Programmable keyboards are often larger than a regular keyboard, with built in utilities that allow the user to change the sensitivity of the keys and other features. Some of the keyboards, with software that comes with them, or additional software allow the user to create a custom keyboard layout. Many alternative keyboards can switch between keyboard and mouse functions with the touch of a key, or can have the mouse functions as a portion of the keyboard. They are available for either Macintosh or Windows, and run simultaneously with the regular keyboard and mouse.
Chording keyboards use a combination of a few keys to create keystrokes for each letter. Most individuals can learn to chord within a few weeks. The user uses the fingers of one hand to press different combinations of keys.
An example of someone using a chording keyboard, plus other examples of how people use computers, is available as a video from the University of Washington. The video lasts 10 minutes and is well worth watching. A link is provided at the end of this session (see resource number 5 below).
Links to resources
The following links will open in a new window
- World-Wide-Web Consortium (W3C) publishes the internationally agreed standards on their web site (http://www.w3c.org [new window] )
- The W3C provides a wide range of tutorials for web coding, these are available at http://www.w3schools.com/sitemap.asp [new window]
- Some examples (scenarios) of disabled users from W3C at http://www.w3.org/WAI/intro/people-use-web/Overview.html
- Refreshable Braille and the Web. Roger Hudson's video of someone using a braille pad to go shopping ( http://www.dingoaccess.com/accessibility/refreshable-braille-and-the-web/ [new window])