Glossary of Terms
This page is meant to give some basic definitions of some of the terms found in this site. These definitions and others can be found in Constructing Accessible Web Sites by Jim Thatcher, et al.
A - B - C - D - F - H - I - M - P - S - U - V - W
Accessibility - the quality of a web site (or any entity) that makes it usable by the largest audience possible, regardless of disability.
Americans with Disabilities Act (ADA) - a United States law passed in 1990 that prohibits discrimination against people with disabilities.
Adaptive Technology - technology used to adapt an already existing computer device or piece of software. A good example would be a Head Pointer that allows a person with limited mobility to use a computer.
Alt Tag (Alt Text) - an alt attribute allows descriptive text to be attached to certain objects on a web page written HTML (usually these objects are images), not only providing visual clues as to the purpose of these objects, but also providing a description that can be read out by a screen reader so that a person with a visual impairment can know what the object is also.
Assistive Technology - equipment or software that assists people with disabilities in performing every-day activities. Examples include screen readers and voice input software.
Bobby - A web site accessibility assessment tool developed by CAST, and located at http://www.cast.org/bobby.
Cascading Style Sheets (CSS) - a means of applying styling/formatting to markup (for example, XML or HTML). This has many advantages over using HTML formatting tags such as <b> and <font>. For a start, CSS formatting is more powerful, and allows more flexibility. Secondly, CSS styles are identified by a unique ID, which is used in the HTML to apply a style to content. If you want to change a style, you need only change its definition in the style sheet, rather than changing every instance of it in the HTML. Lastly, it has great uses for accessibility - for example, you can use an alternative style sheet to make the text on a web site bigger, for the benefit of people with visual impairments.
Disability - a physical or mental impairment that renders tasks performed by an individual more difficult or impossible to achieve.
D-Link - a link that takes the form of a capital D near an image. It provides a longer description of the image or its purpose than is feasible using alt text.
Frames - a feature of HTML that allows a web author to divide a page into two or more separate windows. If the frame does not have a <title> element, or the <title> element is not meaningful, this can cause accessibility issues. In addition, some browsers do not support frames.
Head Pointer - a device attached to the user's head that allows them to move the pointer on the screen, (usually moved by the mouse, a pointing device, the arrow keys, or with the movement of their head). It is useful for people who have limited mobility.
HyperText Markup Language (HTML) - the markup language that is used on most of the World Wide Web to create web pages. The standards for HTML are controlled by the W3C.
Image Maps - areas of an image on a web page that have links to other areas of the Web. Some types of image maps can have alt tags on the areas, while others must have text links.
Multimedia - using a computer to present multiple types of media simultaneously, in an integrated manner. These can include sound, graphics, video, text, animation, or any other form of information representation.
Portable Document Format (PDF) - this was developed by Adobe System, Inc, as a way to publish documents electronically, with good formatting for printing, and document security (documents are generally read-only). Originally it was in an image format, and this presented major accessibility issues. Recently however, Adobe has made large strides in making the PDF format accessible to people with disabilities.
Screen Reader - a computer program that reads the screen to a user. It can be used to surf the Web, write a spreadsheet or document, or just to read pages. It is closely related to Voice Output.
Section 508 - this is a common name for Section 508 of the Rehabilitation Act. This is an amendment to a US law that basically says all Electronic and Information Technology purchased or developed by the US Government must be accessible to people with disabilities.
Universal Design - Designing for the largest audience possible regardless of disability or ability to speak the native language. This is a process rather than an end in itself.
Voice Input - software that recognizes voice commands, and responds accordingly.
Voice Output - computer programs that read the screen to a user.
Voice Recognition - programs that recognize a person's voice and its various characteristics. Closely related to Voice Input.
World Wide Web Consortium (W3C) - an international consortium of companies and organizations involved with the Internet and the World Wide Web, responsible for maintaining web technology standards, such as HTML and CSS. See http://www.w3.org/ for more.
Web Accessibility Initiative - started by W3C and its members, it addresses web accessibility issues. It can be found at: http://www.w3.org/WAI.
Web Content Accessibility Guidelines (WCAG) - these are the guidelines builty by the W3C/WAI to address issues in building accessible web pages.
WAVE - the WAVE was developed by Temple University Institute on Disabilities. It has a number of excellent features that are not included with other assessment tools. It shows which images have the alt attribute missing and it also shows the order in which a screen reader will read a page. It can be found at http://www.temple.edu/inst_disabilities/piat/wave/.
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