Glossary » Accessibility

“D” link

a “description link”; the letter “D” placed next to an image on a web page that links off to a text description of the image. This enables blind users or users of text browsers to understand the content of an…

accessibility aids

assistive technology; tools to help people with disabilities to use computers more effectively. Some general categories of disabilities, and some common aids include:

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ACM SIGCAPH

Special Interest Group on Computers and the Physically Handicapped, part of the Association of Computing Machinery. A professional society to research and apply computer technology to help people with disabilities and to educate the public.

acronym expansion

when a user enters a relevant acronym (or other abbreviation), acronym expansion automatically spells out the entire phrase represented. While this feature can help in any text entry with commonly repeated phrases, it is especially useful to those who have…

adapted computer access

the use of accessibility aids for the disabled with the specific goal of enabling them to effectively use computers.

assistive technology

AT or enabling technology; technology used by those with disabilities or other special needs to help them fully participate in their work and everyday life.

auditory feedback

sounds in response to user activity, such as a click after a keypress, a whoosh accompanying opening and closing windows, or a klunk when a file is deleted. Useful as redundant reinforcement of activities and for those who are visually…

auditory menus

a list of choices presented verbally, as in a telephone answering system, e.g.: “Press 1 to order brochures. Press 2 to report a maintenance problem. Press 3 for more options.”

augmentative and alternative communication

AAC; technologies that enable those with limited speech to communicate.

Baker’s equation

BBEE; Baker’s basic ergonomic equation; an expression describing the factors driving the success of a particular assistive technology:

Likelihood of success (S) = M/(P+C+L+T)

where
M = a user’s motivation to complete a task
P = the physical effort…

blow-suck tube

an input device for users with limited mobility; a blow-suck tube is placed in the mouth and blown through. It can be used in conjunction with a tongue-activated joystick to move a pointer around and make selections.

brain-computer interface

or brain-body interface; an interface directly controlled by brain waves as opposed to physical movement. Current state-of-the-art can only distinguish a few brain states, so such interfaces usually are led by yes-no decisions. These interfaces require training and are currently…

carpal tunnel syndrome

(CTS) a problem with swelling or inflammation around the median nerve in the wrist, causing pain or numbness. Poor wrist support and posture during extensive typing is considered a contributing factor. Some ways to prevent it include improved posture, wrist…

chording

an input mechanism which requires pushing more than one button simultaneously in different patterns to represent different letters or commands.

“Chording keyboards” allow rapid entry of letters and words which can allow faster typing than conventional keyboards and permits one-handed…

closed captions

a visual text view of audio that is in a sound byte or video clip. Closed captions are an excellent provision for the hearing impaired, for nonnative speakers who may find written language easier to understand than spoken language, and…

cognitive impairment

any limitation in the ability to think or reason that affects a person’s capacity to perform a task. Cognitive impairments can be congenital or the result of a head injury, stroke, or disease. Head injuries in particular can result in…

color blindness

an inability to distinguish certain color combinations. About 8% of males and 0.5% of females are colorblind in some fashion, so it is common enough to be a highly-significant factor in design. Red-green color blindness is most common, followed by…

context of use

the situational factors that influence the use and usability of a system, including environmental factors (physical conditions such as space, time, temperature, noise), organizational factors (social network, management and organizational pressures, and work processes), and technical/system factors (network connectivity, system…

cross-platform compatibility

interoperability or platform-independence; the ability for devices or software applications to work with more than one hardware platform or operating system. Broad compatibility with various systems is critical to having a large market for a product (reaching your entire user…

CUU conference

Conference on Universal Usability, a conference that focuses on what it takes to make systems work for everyone, considering the wide diversity of people with different system configurations and from a wide variety of backgrounds, including international and disability issues.…

demographics

statistics representing the range and composition of your target audience, such as total market size and distribution of age, gender, education, income, computer experience, occupation, nationality, and system configurations.

described video

or descriptive video or audio captioning; provides audio descriptions of what appears in a video. Just as closed captions provide display text corresponding to the audio in a video, described video enables someone to hear what is being portrayed visually.…

disability

a mental or physical characteristic that limits the ability for someone to function at full capacity. Disabilities are frequently categorized into:

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disability access

computer equipment and software designed to help people with disabilities to more effectively use them.

diversity

things vary more than you’d ever expect. Users vary by preferences, skills, impairments, interests, language, and culture. Computers vary by operating system, processor speed, screen size, memory, and networking abilities.

Design for diversity, or expect to succeed with only a…