Assistive Technology


Just like most people, people with disabilities use technology to read and write documents, communicate with others, and search for information on the Internet despite a number of issues that can make it difficult to use a computer. These barriers can be grouped into three functional categories: barriers to providing computer input, interpreting output, and reading supporting documentation. Hardware and software tools known as assistive technology have been developed to provide access to people with disabilities.

Mobility Impairments

Among individuals with mobility impairments, some individuals do not have enough use of their hands and arms to operate a standard keyboard or mouse. Individuals who use a wheelchair may not be able to use a standard height computer desk.

Equipment which provides flexibility in the positioning of monitors, keyboards, documentation, and tabletops is useful for many individuals with disabilities. Plugging all computer components into power outlet strips with accessible on and off switches makes it possible for some individuals to turn equipment on and off independently.

Some technology assists individuals with little or no use of their hands in using a standard keyboard. Individuals who have use of one finger, or have access to a mouth- or head-stick or some other pointing device, can control the computer by pressing keys with the pointing device. Software utilities can create "sticky keys" that electronically latch the SHIFT, CONTROL, and other keys to allow sequential keystrokes to input commands that normally require two or more keys to be pressed simultaneously. The key repeat function can be disabled for those who cannot release a key quickly enough to avoid multiple selections. Keyboard guards (solid templates with holes over each key to assist precise selection) can be used by those with limited fine motor control.

Sometimes repositioning the keyboard and monitor can enhance accessibility. For example, mounting keyboards perpendicular to tables or wheelchair trays at head-height can assist individuals with limited mobility who use pointing devices to press keys. 

For individuals who need to operate the computer with one hand, left- and right-handed keyboards are available. They provide more efficient key arrangements than standard keyboards designed for two-handed users.

Some hardware modifications completely replace the keyboard or mouse for individuals who cannot operate these standard devices. Expanded keyboards (larger keys spaced far apart) can replace standard keyboards for those with limited fine motor control. Mini-keyboards provide access to those who have fine motor control but lack a range of motion great enough to use a standard keyboard. Track balls and specialized input devices can replace a mouse.

For those with mobility impairments that restrict their use of a keyboard, keyboard emulation on screen is available, including scanning and Morse code input. In each case, special switches make use of at least one muscle over which the individual has voluntary control (e.g., head, finger, knee, mouth). In scanning input, lights or cursors scan letters and symbols displayed on computer screens or external devices. To make selections, individuals use switches activated by movement of the head, finger, foot, breath, etc. Hundreds of switches tailor input devices to individual needs. In Morse code input, users input Morse code by activating switches (e.g., a sip-and-puff switch registers dot with a sip and dash with a puff). Special adaptive hardware and software translate Morse code into a form that computers understand so that standard software can be used.

Speech input provides another option for individuals with disabilities. Speech recognition systems allow users to control computers by speaking words and letters. Some speech recognition software can be "trained" to recognize specific voices. Abbreviation expansion (macro) and word prediction software can reduce input demands for commonly used text and keyboard commands. For example, word prediction software anticipates entire words after several keystrokes and increases input speed.


Individuals who are blind cannot access visual material presented on the computer screen or in printed materials.

Most individuals who are blind use standard keyboards, however, Braille input devices are available. Braille key labels can assist with keyboard use.

Software called screen readers "read" computer screens and “read” the text aloud. Refreshable Braille displays allow line-by-line translation of screen text into Braille on a display area where vertical pins move into Braille configurations as screen text is scanned. Braille displays can be read quickly by those with advanced Braille skills and are good for detailed editing (e.g., programming and final editing of papers). Braille printers provide "hard copy" output for users who are blind.

Scanners with optical character recognition can read printed material so it can be accessed with a screen reader or via a Braille display or printed Braille. Blind individuals can benefit from electronic versions of documents if they are delivered in an accessible format.

Low Vision

For some people with visual impairments the standard size of letters on the screen or printed in documents are too small for them to read. Some people cannot distinguish one color from another.

Most individuals who have visual impairments can use standard keyboards, but large print keytop labels are sometimes useful.

Screen magnification software magnifies information displayed on the screen, allowing individuals with low vision to use standard word processing, spreadsheet, email, and other software applications. For individuals with some specific visual impairments, the ability to adjust the color of the monitor or change the foreground and background colors is also of value. For example, special software can reverse the screen from black on white to white on black for people who are light sensitive. Anti-glare screens can make screens easier to read. Some low vision individuals use voice output.

Learning Disabilities

Software that aids in efficient and accurate input can be useful to some students with learning disabilities. Some people can compensate for high rates of input errors by using spell checkers, thesauruses, and grammar checkers. In addition, word prediction programs (software that predicts whole words from fragments) have been used successfully by students with learning disabilities. Similarly, macro software which expands abbreviations can reduce the necessity to memorize keyboard commands and can ease the entry of commonly used text.

Some individuals with learning disabilities find adaptive devices designed for those with visual impairments useful. In particular, they may use large-print displays, alternative colors on the computer screen, and voice output. People who have difficulty interpreting visual material can improve comprehension and the ability to identify and correct errors when words are spoken or printed in large fonts.


Discussion Questions

  • Do you know people that use assistive technology? What do they use?
  • How might individuals that don’t have disabilities benefit from assistive technology?
  • As things like speech recognition software are used more widely rather than just by people with disabilities, some have argued that “assistive technology” should be referred to simply as “technology”? What are the benefits or drawbacks of using the term “assistive technology” or “technology”? What term do you prefer?

Project Ideas

  • Ask students to familiarize themselves with one type of assistive technology and give a demonstration to the course. To do this you may want to encourage students to either use software that is freely available or built in to their operating system or to use something that is freely available on your campus.
  • Match students with an individual that uses AT. Have students meet with the individual, see them use a computer, and then try to use a webpage or other technology that the students have designed. Have students make their project more usable or welcoming to individuals with disabilities.