A-Prompt (Accessibility Prompt)

 A tool developed to assist Web authors in improving the accessibility and usability of HTML documents. It is made available through a joint collaboration between the Adaptive Technology Resource Centre at the University of Toronto and the TRACE Center at the University of Wisconsin. Although it's free, it's currently only available for the Windows platform. For more information visit the A-Prompt site.

Abbreviation Element

in XHTML the title attribute is used in conjunction with abbr element to give the long form of an abbreviation, allowing screen readers to speak the full word or phrase. Use of <abbr> element is part of the University of Minnesota Web Accessibility Standards because screen-readers sometimes attempt to pronounce abbreviations. It is also in WCAG (priority 3). Example markup: <abbr title="University of Minnesota Duluth">UMD</abbr> For more information visit  Abbreviations & Acronyms.

Accessibility (Web)

Accesskey

An accesskey is an XHTML attribute. It is meant to help users who navigating without a pointing device, such as a mouse. Access keys are intended to be a means of specifying a keyboard shortcut for moving to a link, form component or other tabbable object, using the following HTML elements - a, area, button, input, label, legend or textarea. Use of accesskey is controversial. The current opinion of many accessibility experts is that, accesskeys mostly work against accessibility. And because of many conflicts, defining accesskeys seem to be a waste of time unless you are designing for a controlled environment such as an intranet.

Adaptive Technology

Sometimes known as assistive technology. It is software or hardware that has been specifically designed to assist people with disabilities in carrying out daily activities. Assistive technology includes wheelchairs, reading machines, devices for grasping, etc. In the area of Web Accessibility, common software-based assistive technologies include screen readers, screen magnifiers, speech synthesizers, and voice input software that operate in conjunction with graphical desktop browsers (among other user agents). Hardware assistive technologies include alternative keyboards and pointing devices.

Affinity Diagram

Affinity diagramming is a categorization method where users sort various concepts into several categories. This usability method is used by a team to organize a large amount of data according to the natural relationships between the items. Basically, you write each concept on a Post-It note and tack them onto a wall. Team members move the notes to groups based on how they feel the concept belongs with other concepts. For more information visit: Affinity Diagrams.

AJAX

 AJAX stands for or Asynchronous Javascript and XML. It's a way to utilize the abilities of Javascript, the Document Object Model, and XML to create interactivity on the web. For more information visit: AJAX (Asynchronous JAvaScript + XML or Asynchronous JAvascript using XMLHttpRequest)

Alt Attribute

 An alt attribute is used to specify alternative text. It is used to replace an image. That means that it serves the same function as the image. Users of screen-readers, language translation applications or some hand-held devices cannot directly access pictures and other graphics. Similarly, some users choose to turn picture loading off- especially those with slower dial-in connections. These users rely on alt attributes.

Alt Tag

 The term "alt tag" is sometimes incorrectly used instead of the correct term " alt attribute". Actually as hard core developers will tell you, in HTML their is no such thing as an "alt tag". Technically, tags are things like <p> or </p> that you use to mark up your page and the alt attribute sits inside a tag, like this: <img alt="" / >. Calling an attribute a tag is a common mistake.

Alt Text

 Alt text is generally a phrase or short sentence that forms the content of the alt attribute. It is contained within the quotation marks. This simple idea has great power. The wrong or inadequate alt text can make your web site inaccessible to people with disabilities.

Alternate Styleshee

These style sheets can be selected by the visitor as alternatives to the preferred style sheet. This allows the visitor to personalize a site and choose his or her favorite scheme. They can also be used for accessibility (larger fonts etc).

Alternative Interface Access Protocol (AIAP)

 A technology under development by the National Committee on Information Technology; it will allow a user to get web pages in the form they choose for the device they choose

Americans with Disabilities Act

United States public law enacted in 1990 guaranteeing rights for people with disabilities. This law mandates reasonable accommodation and effective communication.

Amyotrophic Lateral Sclerosis (ALS)

  A fatal, neuromuscular disease that causes rapid deterioration of minor cells in the brain and spinal cord, ultimately leading to impairment of mobility, speech, and respiratory functions. It is more commonly known as Lou Gerhig's disease.

Anti-alias

 Anti-alias is a feature used to smooth out jagged edges of an electronic graphic image.

Applet

 A Java program or application designed to be embedded in, and invoked from, a web page, or other application. It cannot be run by itself.

Array

In programming, an array is an indexed collection of data values. For instance in PHP, and array is a container for a number of variables which all have the same name, but each has a different index. Each member of the array is called an element. You can create arrays in the same way you create variables, as long as you remember to put square brackets around them to denote the index. By default, arrays are zero-based, that is, the first element of the array has an index of zero.

Assignment Operator

In programming, assignment operators assign a value to a variable. The equal sign is the most common assignment operator.

Assistive Technology

  Sometimes known as adaptive technology. It is equipment or software that assists people with disabilities in performing every day activities. Examples include screen readers and voice input software.

Attribute

  In XHTML, an attribute is a characteristic of an element.

Audio Description

 An audio description is narration, spoken out loud. It explains visual details. This allows visual content to be accessible to the blind or those with vision impairments. Audio descriptions of visual content is important if, for example, a video provides content that is relevant to the overall understanding of the video but is not available/ recognized through the default audio already present. For example an audio description can take a movie, and talk you through it. The narrator tells you what is happening on the screen what you can not figure out just from the soundtrack.

Authoring Tool

 A software application used to create web pages and web sites.

Backward Compatible

Design that continues to work with earlier versions of a user agent, language, program, etc.

Baseline

Baseline (in WCAG 2.0) is a set of technologies that a user agent (browser, media player, screen reader etc.) is assumed to support and have enabled. It may be set by the author or higher authority. When an author makes a WCAG 2.0 conformance claim, they must specify the baseline that they are using to make that claim. The author is claiming that their content will meet WCAG 2.0 at the stated level of conformance if a user’s agent can support those (the baseline) technologies.. It's important to note that the baseline consists of technologies that are assumed to be supported by user-agents, and not specific user agents. The concept of baseline is based around trust. It is very possible to abuse baselines by declaring technologies that are not widely supported and not widely supported by assistive technology. For more information visit About Baselines and WCAG 2.0.

Blindness

Blindness includes a variety of conditions involving extreme (but not complete) or complete loss of vision.

Block Level Element

Block-level elements typically contain inline elements and other block-level elements. When rendered visually, they usually begin on a new line. Examples of block level elements include paragraphs, headings, divs, and blockquotes.

Bobby

A discontinued website accessibility assessment tool designed to locate and identify certain accessibility problems within web pages, so that a web developer could repair those problems. It analyzed web pages and checked for those accessibility problems that can be checked for automatically. It was a good first pass for checking your web pages for accessibility.

Box Model

In Cascading Style Sheets, the box model refers to the rectangular boxes that are generated for elements in the document tree and laid out as specified in the visual formatting model. Every element generates a box, which is call the element box. As the word "box" implies, these are rectangular in shape Each box is made up of a number of parts. In the normal document flow, the element boxes of block-level elements cannot overlap each other (floats and positioning are the exceptions). In other words, the way a page is laid out depends on the size of each and every box. Going down the page, in broad terms, each box begins just below where the previous one ends. For more information See Box Model.

Braille

A system of writing for individuals who have visual disabilities. The Braille system includes letters, numbers, and punctuation made up of raised dot patterns.

Breadcrumbs

Breadcrumbs are a type of web navigation where current location within the website is indicated by a list of pages above the current page in the hierarchy, up to the main page. It not only shows users where they are currently located in the site's architecture, but it also lets them back up levels one at a time. It is a recursive path. For more information see: Breadcrumbs

Browser

 The software on a computer that allows websites to be rendered so they can be "read" by users. This maybe a browser that renders things visually, in a manner confined to text only, or in any other manner that may be appropriate, such as voice output..

Browser Style Sheet

This is the default style sheet within a browser. If a designer declares no style rules, the defaults from the browser are applied. Most browsers apply style sheets to all web documents. Although these style sheets vary from browser to browser, they all have common traits like black text, blue links, purple visited links etc. These are referred to as the "default" browser style sheet.

Captions

Captions are text transcripts that are synchronized with other audio or visual tracks. Captions convey information about spoken words and non-spoken sounds such as sound effects. They benefit people who are deaf or hard-of-hearing, and anyone who cannot hear the audio (e.g., Someone in a noisy environment). Captions are generally rendered graphically above, below, or superimposed over video. Captions can be closed or open. Closed captions are encoded or invisible and must be decoded or made visible. Open captions can't be turned off.

Card Sorting

Card sorting is a categorization method where users sort cards depicting various concepts into categories. You start with a list of all the items you want sorted. Write down each item on a separate index card. Give your user(s) the stack of cards and have them divide the cards up into piles, telling them that the cards should be grouped the way they (the users) best see fit. This technique is best used in the early stages of development. For more information see: Card Sorting.

Cascade

The CSS cascade assigns a weight to each style rule. When several rules apply, the one with the greatest weight takes precedence. You can think of some rules coming from "higher up" in the cascade; these combine with the rules at the next level down, and the result combines with the next level, and so on, until finally you have the actual rules to be applied to the document pooled at the "base" of the cascade. The cascade is the mechanism by which rules from different places are combined to create an über-stylesheet

Cascading Style Sheets (CSS)

Style sheets refer to a set of rules that allow you to control how you would like your document to be rendered. It is a mechanism to primarily separate presentation from content. With the HTML and style sheets approach, structured content goes into the HTML document, and the appearance, or presentation information goes into a style sheet. CSS allow you to control the rendering of elements on a web page without compromising its structure. Before CSS , nearly all of the presentational attributes of an HTML document were contained within the HTML code; all font colors, background styles, alignment specification, boxes, borders, and sizes had to be explicitly described, often repeatedly, in the midst of the HTML code. CSS allows web designers to extract this information, resulting in considerably simpler HTML code, supplemented by an auxiliary style sheet written in the language of CSS . The structure and semantic markup is restricted to the HTML code, while the presentational markup is restricted to the CSS code. For more information visit: Cascading Style Sheets.

Center for Applied Special Technology (CAST)

The organization that originally developed the website accessibility checker Bobby. For more information, see www.cast.org.

Child

In HTML, an element A is called the child of element B if an only if B is the parent of A.

Chunking

Chunking is the way that the brain deals with complexity. Humans short term memory can retain, at most, only about 7±2 things at one time according to George A. Miller. For more information see: Chunking.

Click Here

The phrase "click here" is a bad linking practice. It makes navigating the web difficult for both sighted and unsighted users. Link text should be meaningful enough to make sense when read out of context. For more information see: "Click here" don't use it...

Cognitive Disability

A disability involves a person's capacity for processing information and knowledge. For more information see Cognitive Disabilities.

Cognitive Walkthrough

A cognitive walkthrough is a review technique where you construct task scenarios from a specification and get a user to role play the part of walking through the task. They act as if the interface was actually built and they (in the role of a typical user) was working through the tasks. Each step the user would take is scrutinize.

Color Contrast

Color contrast refers to how close hues are in value. The human eye requires good contrast for visibility and legibility. Contrast creates visual interest and helps deliver accurate information. It can make a big difference on a web page. Colors that are close in value tend to blur together, and their borders "melt." This can create legibility problems. For example, black text on a dark blue background is difficult to read.

Color Deficiency

Color deficiency is a lack of the ability to discriminate between colors. Designs that rely totally on color to convey essential information will be inaccessible to a small percentage of women and a larger percentage of men

Color Deficiency

Color deficiency is a lack of the ability to discriminate between colors. Designs that rely totally on color to convey essential information will be inaccessible to a small percentage of women and a larger percentage of men

Color Saturation

Color saturation refers to the intensity of a color.

Composite Capabilities/Preference Profiles (CC/PP)

CC/PP profiles are a method that allows a description of device capabilities and user preferences to be delivered to the server, so that content can be adapted to the device according the preferences of the user.

Consistency

Consistency is the quality of an interface when it behaves in ways users expect. It means that users can apply the knowledge obtained in some previous experience to enhance current performance.

Content Management System

A content management system separates the content of a Web site from its code, allowing nontechnical users to update, approve and post content

Contextual Inquiry

Contextual inquiry is a structured field interviewing usability evaluation method. It involves conversation as well as observation. Contextual inquiries requires a high degree of skill from the usability specialist, in order to ask appropriate questions without interrupting the participants' work flow or influencing their responses. Sometimes two usability specialists are used for a contextual inquiry project, one to conduct the interview, and one to observe and record participant behavior. You can discover unmet needs and understand existing behaviors in greater depth with this method.

Contextual Selector

In CSS, a Contextual selector is a type of selector that selects by the context in which an element or attribute occurs in the markup structure of a document.

Control Structures

In programming, control structures are used to control the logical flow through a script..

Controlled Vocabulary

A controlled vocabulary is a list of terms that have been specified explicitly. All terms in a controlled vocabulary should have a clear-cut, non-redundant definition.

D link

A "description link" that takes the form of a capital D and is located near an image. It is linked to a separate page containing a description of the image. This enables blind users or users of text browsers to understand the content of an image without actually seeing it.

Data Table

A table that is used to present data in a tabular or spreadsheet format. This contrasts with a layout table that uses the same construct for a different purpose. In a data table contents of a cells are related to cell contents in adjacent cells.

Deafness

 A condition of a person who can not hear at all.

Declaration

In CSS, a declaration is part of a statement or rule. It is the portion of the statement which suggests to a browser how selected elements should be rendered. A declaration contains one or more properties the individual pieces of style to be applied to the selected element. It consists of pair of property and value parameters.

Deep Linking

Deep Linking

Deep links are links that go directly to an inner page of a website rather than the homepage. It enables direct linking to highly appropriate and specific content.

Degrade Gracefully

An element on a web page is said to 'degrade gracefully' if ignoring it does not prevent content on the page from being obtainable and functional.

Deliverable

In project management, deliverables are the output of what you are doing. It refers to the defined end products, results, or services of a project.

Deprecated

A deprecated element or attribute is one that has been outdated by newer constructs. Deprecated elements may become obsolete in future versions of HTML . Authors should avoid using deprecated elements and attributes. The W3C recommends in Checkpoint 11.2 that deprecated elements and attributes not be used, mostly because they force styles and design upon a user instead of using style sheets that allow a user to override the default style. A listing of deprecated elements and attributes can be found at: http://www.w3.org/TR/REC-html40/index/elements.html and http://www.w3.org/TR/REC-html40/index/attributes.html.

Descendant Selectors

At times, authors may want selectors in CSS to match an element that is the descendant of another element in the document tree (e.g., "Match those EM elements that are contained by an H1 element"). Descendant selectors express such a relationship in a pattern. A descendant selector is made up of two or more selectors separated by whitespace. A descendant selector of the form "A B" matches when an element B is an arbitrary descendant of some ancestor element A.

Device Independence

For Web content to be device independent, it should be possible for a user to obtain a functional presentation associated with its Web page identifier via any access mechanism.

Digital Divide

The gap that exists between those who have access to Electronic and Information Technology, and those who do not.

Disability

According to the Americans with Disabilities Act, " The term means, with respect to an individual (A) a physical or mental impairment that substantially limits one or more of the major life activities of such individual; (B) a record of such an impairment; or (C) being regarded as having such an impairment."

Disability Discrimination Act (DDA)

A name shared by two laws passed in Australia (1992) and the United Kingdom (1995). They both prohibit discrimination against people with disabilities. The goal is that a functional presentation should be possible via any access mechanism. The method of presentation may vary according to the different access mechanisms, but the possibility of a functional presentation should always exist.

Dithering

In computer graphics, dithering is a method of creating additional colors and shades from an existing palette by interspersing pixels of different color in computer graphics to create additional colors and shades from an existing palette by interspersing pixels of different colors

Doctype Switching

Switching is the mechanism by which browsers examine the DOCTYPE (or lack thereof) contained in a document, and picks a rendering mode to match it. Typically, older or malformed DOCTYPEs cause browsers to enter "quirks" mode, which emulates historical authoring practices built around the flaws found in older browsers. Newer DOCTYPEs will trigger "strict" mode, where they attempt to hew as closely as possible to the abbr title="World Wide Web Consortium">W3C recommendations in order to deliver a more consistent cross-browser experience. This lets authors decide which mode to use, a decision which is generally fueled by their target audience. The browser doesn't actually use the DOCTYPE to validate the content -- it only uses this string to toggle specific behavior of the renderer.

Doctype, Document Type Definition (DTD)

A file that defines how applications interpreting a document should present the content. It is used in HTML , XML , and other Markup languages. A DOCTYPE is a means of specifying what syntax a web page uses. Include a document type declaration at the beginning of a document that refers to a published DTD (e.g., the strict HTML 4.0 DTD). The document type declaration should be appropriate to the markup language you are using. It should appear at the very beginning of an HTML document in order to identify the content of the document as conforming to a particular HTML DTD specification. For more information see: Doctype.

Document Tree

The tree of elements encoded in the source document. Each element in this tree has exactly one parent, with the exception of the root element, which has none.

Dots Per Inch (DPI)

Dots Per Inch is a term that also refers to printing and the amount of ink that actually is placed upon the print medium. Dots Per Inch is a property of a print graphic and determines how it prints - its size and quality. Color printing isn't done in continuous color, it's done with individual dots of Cyan, Magenta, Yellow and Black (CMYK), lots of them, giving an impression of continuity. These are the dots in dpi. Dots per inch (number of pixels) also measures resolution on output devices such as monitors and printers. The horizontal and/or vertical density of the output device, is arrived at by dividing the resolution of the device by the physical dimensions of its imaging region. A Mac monitor is typically 72 dpi. A PC monitor is typically 96 dpi. Most laser printers have output resolution of 300-600 dpi and produce good results with images which have image resolution of 72-150 ppi.

Dyslexia

A language based learning disability that is often characterized by difficulties with understanding written language, and being more attuned to a graphical or object based learning style.

Electronic and Information Technology (EIT)

This term encompasses any of a number of devices and device types. It is basically any device or technology that uses electronic means to transmit and present information to the user. Examples include Computers, PDAs, cell phones, information kiosks, televisions, and many other devices.

Element

In XHTML, an element is of node in the document tree. A XHTML element is represented by a start tag like <h1> and an end tag like </h1>..

Em Unit

In CSS, an' em' is what is referred to as a relative unit, like percentages. Good design allows scaling and uses relative size values; it almost always provides excellent implementation of ems. An 'em' is equal to the computed value of the 'font-size' property of the element on which it is based. The exception is when an 'em' occurs in the value of the 'font-size' property itself, in which case it refers to the font size of the parent element. It may be used for vertical or horizontal measurement.

Em-box

The box around a font character of a given 'size' as designed by the designer. It is sometimes referred to as an em-square. The theoretical square that glyphs are designed upon. Its height is the intended distance between lines of type in the same type size. It is the design grid on which the glyph outlines are defined.

Embedded Style Sheet

An embedded style controls the appearance of a single document. CSS rule(s) are placed in the head of the document via the style element. Embedded styles can be really helpful when you are first learning to code CSS, because it is very easy to edit and troubleshoot the code. Similar to inline styles, embedded CSS defeats the purpose of separating content and presentation. An embedded style sheet can be useful when a single document has a unique style. If the same style sheet is used in multiple documents, then an external style sheet would be more appropriate. Embedded styles are sometimes referred to as internal styles.

Equivalent

Content is "equivalent" to other content when both fulfill essentially the same function or purpose upon presentation to the user. In the context of this document, the equivalent must fulfill essentially the same function for the person with a disability (at least insofar as is feasible, given the nature of the disability and the state of technology), as the primary content does for the person without any disability.

Ethnographic Study

See Field Observation.

Extensible Markup Language (XML) -See XML.

An external type of style sheet is a separate file apart from the HTML file(s). The external style sheet is given a .css extension. It is associated to the HTML document using a link element or an @ import directive in the head of the html document. Any html document associated to an external style sheet gets the styles, and that is where the maintenance power of CSS is found. Not only do external style sheets allow reuse of rules within one specific document. They allow the style sheet itself to be shared across multiple documents. Using external CSS allows you to maintain a single style sheet for an entire site.

Eyetracking

An eyetracking device observes a person's pupil to determine the direction of their gaze. It can aid in learning the relative intensity of a user's attention to various parts of a web page. For more information see: Eyetracking.