DEMOS Project - Accessibility Guide: Glossary

Glossary

[ A ] [ B ] [ C ] [ D ] [ E ] [ F ] [ G ] [ H ] [ I ] [ J ] [ K ] [ L ] [ M ] [ N ]
[ O ] [ P ] [ Q ] [ R ] [ S ] [ T ] [ U ] [ V ] [ W ] [ X ] [ Y ] [ Z ]

[A]

Accessible: A webpage and its content are accessible when it can be accessed by people with disabilities.

Applet: A small program that runs within another application, for example within the browser. Java is one of the main languages used for creating Web-based applets.

ASCII art: Images created with text characters and symbols. One example are emoticons used in email and chat, e.g. happy :) and sad :(

Assistive technology: Software or hardware that has been specifically designed to assist people with disabilities. This includes screen readers and magnifiers, speech synthesizers, braille printers, voice input software. Hardware assistive technologies include alternative input devices (alternative keyboards, mice, etc.)

Authoring tool: A program that helps to write hypertext or multimedia applications. (see WYSIWYG)

[B]

Backward compatible: Design that works in earlier versions of a software program, e.g. in an older version browser.

Browser: A computer program that opens and displays web pages. Some of the browsers currently in use: Netscape, Opera, Internet Explorer.

[C]

Cascading Style Sheets (CSS): ...give both web site developers and users more control over how pages are displayed. Designers and users can create style sheets that define how different elements, like headers and fonts appear, basically separating visual design from structure. HTML's visual design capabilities are limited and CSS should be used to specify fonts, colours, headers, positioning of text, etc.

[D]

Degrade: According to W3C recommendations web pages should 'degrade gracefully', meaning that they should be displayed across different platforms and browsers in such a way that the content of a page still makes sense. For example, web sites using style sheets for layout should still display text, images, navigation and content in a linearised logical order when viewed in old or non-standard compliant browser where style sheets or certain types of mark-up are not supported and therefore ignored. (see also: Linearised table)

Deprecated: A deprecated element or attribute is one that was valid in earlier version of HTML but has since been replaced by other techniques. These elements will eventually become obsolete but user agents are expected to still support them to ensure backwards compatibility. A prominent example is the FONT tag and other presentational attributes. It should be avoided and CSS used instead, but browsers will still interpret it correctly.

Dynamic HTML (DHTML): DHTML refers to a mixture of techniques used in web design including CSS and JavaScript.

[G]

Graphical user interface (GUI): a graphical user interface to a computer like the Macintosh or Windows operating system, as opposed to a textual one like the command interface of the DOS operating system.

[H]

HTML: Hypertext Mark-up Language. The standard language for creating Web documents. HTML is used to give text a logical structure, specifying paragraphs, headings, sub-headings, bullet list, etc. According to the latest HTML specifications (HTML 4 and XHTML), presentational styles like font size or colour are no longer allowed within HTML mark-up. These styles should be specified in Cascading Stylesheets (CSS).

Hypertext: Text that contains links to other documents.

[I]

Image Map: Image maps are mostly larger images that include 'hotspots' (clickable areas), e.g. a map of Europe, where clicking on a country will take the user to the corresponding page. For better accessibility, image maps should be accompanied by text links.

Information Architecture (IA): This term refers to the organization of a website's structure and content, the labelling and categorizing of information and the design of navigation and search systems. Information Architects are the librarians of web development. The aim is to help users find information and accomplish their task.

[J]

JavaScript: A scripting language used to add interactive features to web pages.

[L]

Linearised table: The content of table cells is displayed as a series of paragraphs, one after another. (see also: transform gracefully)

[M]

Metadata: "Data about data". Data which provides information about a resource.

Metatags: Metatags, which are embedded in the HTML code of a webpage, provide useful information that are not defined by other HTML elements. Their function is to provide information about a document and about a document's content. Search engines use this information to categorize, prioritize and rank websites.

Multimedia: ...combines text, graphics, video, animation, and sound.

[N]

Navigation: The means by which a user can navigate the content of a page or site. Navigation usually consists of a collection of links to sections and subsections of a site. Often a sitemap is provided as an overview. Tables of contents usually list links to subsections of a site or sections of a specific document.

[P]

Pop-up window: A pop-up window is a small browser window that is usually opened by some JavaScript event. Predominantely used for advertising.

Presentational mark-up: Presentational mark-up is used to create stylistic effects such as font styles, bold or italic text. (Note: <strong> and <em> are not presentational mark-up. They convey information that is independent of a particular font style.) (see also: Structural mark-up)

[R]

Rendering: This term refers to how information in a document is presented according to the medium, e.g.'drawn' on the screen, spoken by a screenreader or displayed in a printed version.

[S]

Screen magnifier: A software program used by people with low vision that magnifies a portion of the screen.

Screen reader: A software program that reads the contents of the screen aloud to a user. Usually used by blind and visually impaired people. Screen readers cannot read text that is part of an image.

Structural mark-up: Structural mark-up is used to give an HTML document a logical structure, using physical elements like paragraphs (<p>) and headers (<h1>, <h2>, etc.) (see also: Presentational mark-up)

Style sheet: (see: Cascading Style Sheets)

[T]

Tabular data: Also 'tabular information' or 'data table'. Information displayed in a table where a logical relationships exists between data arranged in columns and rows.

Tag: A command that specifies how a document, or a portion of the document, should be formatted. In HTML most tags consist of an opening and a closing tag and look like this: <em>emphasized text</em>. The text between these tags will be displayed on screen in italics and audibly emphasized by a screenreader.

Transform gracefully: According to W3C recommendations web pages should 'transform gracefully', meaning that they should be displayed across different platforms and browsers in such a way that the content of a page still makes sense. For example, web sites using style sheets should still display text, images, navigation and content in a linearised logical order when viewed in old or non-standard compliant browser where style sheets or certain types of mark-up are not supported and therefore ignored. (see also: Linearised table)

[U]

User agent: ...the software that interprets HTML documents. This includes graphical browsers, text-only browsers, non-visual browsers like audio or braille browsers, etc.

User Interface: ...the point of communication and interaction between computer and human. The UI design should provide a positive user experience by providing clues about what to do and how to do it.

[V]

Validation: ...ensures that the underlying code of a webpage is compliant with the current HTML specifications and standards. Various validation packages can analyze web pages and style sheets for errors in the code or check for accessibility issues.

[W]

Web Accessibility Initiative (WAI): Addresses accessibility issues in the technology of the Web, creates guidelines for accessible web design and for the development of technologies and tools, develops evaluation and validation tools for accessibility and conducts education and research.

Well-formed: A documents is well-formed if it is structured according to rules defined by standards and recommendations. (see W3C)

World Wide Web Consortium (W3C): An international industry consortium responsible for developing common protocols and standards that promote the web's evolution and ensure its interoperability.

WYSIWYG: ...stands for 'What You See Is What You Get'. WYSIWYG HTML Editors like Dreamweaver or Frontpage let you create web pages by displaying exactly how it will look in a browser. Knowledge of HTML is not necessary. The use of WYSIWYG editors is problematic because of their use of non-standard, proprietory and deprecated mark-up.

[X]

XHTML ( Extensible Hypertext Markup Language): A hybrid between HTML and XML. It is a way of making HTML documents compliant with the new XML standard.

XML (Extensible Markup Language): XML is a specification created by the W3C to eventually replace HTML. It is similar to HTML but is "extensible" in that custom tags can be defined and added.

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