Glossary

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Attention Capture Pattern(also: Attention Capture, Attention Grabbing Design)

A design element on a website intentionally crafted to draw users' attention toward content that serves the site's interests rather than the user's goals. Examples include bright promotional banners, flash sale notifications, pop-up offers, and visually prominent recommendation…

Audience Modelling(also: Audience Modeling, User Modelling)

The practice of characterizing and formally describing distinct groups of users and their interaction characteristics to inform the design and evaluation of web interfaces. In accessibility, audience modelling involves identifying the specific abilities, disabilities, devices,…

Audio CAPTCHA(also: Audio HIP, Audio Human Interaction Proof)

An auditory alternative to visual CAPTCHAs, typically presenting distorted spoken letters, numbers, or words that users must transcribe. While intended as an accessible alternative for blind users, research shows audio CAPTCHAs have success rates of only 43-50% for screen reader…

Audio Enriched Links(also: AEL, Audio Link Preview)

A JAWS screen reader extension that provides spoken previews of linked web pages before a blind user follows a hyperlink. When activated on a focused link, the system fetches the destination page in the background and speaks a summary including the page title, its relationship…

Audio HTML Access(also: AHA, AHA Framework)

Audio HTML Access (AHA) is a framework of principles for choosing sounds to use in audio-based HTML interfaces, developed by Frankie James at Stanford University in the late 1990s. The framework provides structured guidelines for selecting audio cues to represent web document…

Aural Browsing(also: Aural Navigation, Aural Web Browsing)

Aural browsing refers to the experience of navigating and consuming web content through auditory output, primarily via screen readers that read page content aloud sequentially. Unlike visual browsing where users can scan and skim pages at a glance, aural browsing is inherently…

Aural CSS(also: Aural Cascading Style Sheets, CSS Aural Properties, CSS Speech)

Aural CSS refers to CSS properties designed to control the auditory presentation of web content, originally specified as the "aural" media type in CSS2 and later revised as the "speech" media type in CSS3. These properties allow web authors to specify how content should be…

Aural Glancing

The auditory equivalent of visually glancing at a web page — the ability for screen reader users to quickly get a sense of what sections and content are available on a page without being forced to listen to every element serially. Aural glancing aims to bridge the fundamental…

Authoring Tool(also: Web Authoring Tool, Content Authoring Tool)

An authoring tool is any software application used to create or modify web content, ranging from code editors and content management systems (CMS) to visual page builders and social media platforms. The W3C's Authoring Tool Accessibility Guidelines (ATAG) address two aspects of…

Authoring Tool Accessibility Guidelines (ATAG)(also: ATAG, ATAG 2.0)

A W3C Web Accessibility Initiative standard that provides guidelines for designing authoring tools — such as content management systems, website builders, and code editors — that are both accessible to authors with disabilities and capable of producing accessible web content.…

Automated Accessibility Testing(also: Automated A11y Testing, Accessibility Scanning)

The use of software tools to programmatically check web content against accessibility guidelines such as WCAG. Tools like Axe, WAVE, Google Lighthouse, and AChecker translate accessibility rules into automated checks applied to HTML elements. While efficient for detecting…

Automated Accessibility Testing(also: Automated Testing, Accessibility Scanning, A11y Testing)

The use of software tools to programmatically check web content against accessibility guidelines such as WCAG, identifying issues like missing alternative text, insufficient color contrast, empty links, and missing form labels. While automated tools such as WAVE, axe, and…

Automated Web GUI Testing(also: AWGT, Automated GUI Testing, Web Crawler Testing)

Automated Web GUI Testing (AWGT) refers to software testing approaches that automatically explore web applications by performing GUI interactions such as clicking and form input, without requiring manually written test scripts. AWGTs build a state model of the application during…

Automated accessibility testing(also: Automated a11y testing, Accessibility checker)

The use of software tools to automatically evaluate digital content against accessibility standards, checking for issues like missing alt text, colour contrast violations, missing form labels, untagged PDF structure, and incorrect heading hierarchy. Automated testing can…

Automatic Alt Text(also: AI-generated Alt Text, Auto Alt Text, Machine-generated Alt Text)

Alternative text for images that is automatically generated by artificial intelligence systems using computer vision and natural language processing. Platforms like Microsoft PowerPoint, Facebook, and Twitter have incorporated automatic alt text features to increase image…

Axe(also: axe-core, Deque Axe)

An open-source accessibility testing engine developed by Deque Systems that checks web content against WCAG and other accessibility standards. Axe can be integrated into browsers (via browser extensions), development workflows (via axe-core library), and testing frameworks (via…

BETSIE(also: BBC Education Text to Speech Internet Enhancer)

BETSIE (BBC Education Text to Speech Internet Enhancer) was an early web accessibility tool developed by the BBC as a CGI Perl script that produced text-only versions of web pages optimized for users of text-to-speech systems. BETSIE handled frames by serializing them,…

BS 8878(also: British Standard 8878, Web Accessibility Code of Practice)

A British Standard published in 2010 that provides a code of practice for web accessibility. BS 8878 defines a 16-step process for implementing web accessibility within organisations, taking a user-centred approach that goes beyond technical conformance with WCAG. It emphasises…

Barrier Impact Factor(also: BIF, Accessibility Barrier Impact)

A metric for measuring the severity of web accessibility barriers by weighting detected errors according to which assistive technologies and disability groups they affect. The BIF is calculated by summing the product of the number of errors and a weight value for each affected…

Barrier Walkthrough Method(also: BW Method, Barrier Walkthrough)

An accessibility evaluation method developed by Giorgio Brajnik that groups Web Content Accessibility Guidelines (WCAG) success criteria by user categories such as blind users, people with low vision, and motor-impaired users. Unlike standard WCAG audits that evaluate all…

Bidirectional Interface(also: BiDi Interface, RTL Interface)

A user interface designed to support both left-to-right (LTR) and right-to-left (RTL) text directions, essential for languages such as Arabic, Hebrew, Farsi, and Urdu. Bidirectional interfaces must handle not only text direction but also the mirroring of layout elements,…

Blackboard Ally(also: Ally)

A commercial accessibility-checking and alternative-format-generation service from Anthology (Blackboard) that integrates with learning management systems such as Blackboard Learn, Canvas, Moodle, and Brightspace. Ally scans uploaded course materials, reports accessibility…

Bobby(also: Bobby Worldwide, Watchfire Bobby)

Bobby was one of the earliest and most widely used automated web accessibility testing tools, developed by the Center for Applied Special Technology (CAST) and later acquired by Watchfire (subsequently IBM). Launched in the mid-1990s, Bobby checked web pages against WCAG 1.0…

Breadcrumb(also: Breadcrumb Navigation, Breadcrumb Trail, Breadcrumbs)

A secondary navigation pattern that displays the user's current location within a site or application hierarchy as a series of linked steps, typically separated by arrows or slashes. Breadcrumbs help users understand where they are in a structure and navigate back to higher…

Brickfield Accessibility Toolkit(also: Brickfield Toolkit)

An accessibility scanning and reporting tool for Moodle developed by Brickfield Education Labs. It is distributed on a freemium model: a community-edition set of scanners is integrated into the Moodle core Accessibility Toolkit, while advanced institutional features (bulk…

Brightness Contrast(also: Luminance Contrast, Perceived Brightness Difference)

The difference in perceived brightness between two colors, typically between text and its background. Brightness contrast is a key factor in readability, especially for people with low vision, color vision deficiencies, or those viewing content in challenging lighting…

Browser Extension(also: Browser Plugin, Browser Add-On)

A software module that adds functionality to a web browser, typically installed from a browser's extension store. Browser extensions are a common delivery mechanism for accessibility tools because they can modify webpage content and behavior without requiring changes to the…

Browser Extension Accessibility(also: Accessible Browser Extension, Assistive Browser Extension)

The design and development of web browser extensions that either enhance the accessibility of existing web content or are themselves fully accessible to users of assistive technologies. Assistive browser extensions can augment web pages with additional accessible content,…

Browser Helper Object(also: BHO)

A plugin module for web browsers (originally Internet Explorer) that loads with each browser instance and has access to the Document Object Model and browser events. In accessibility contexts, BHOs have been used to implement client-side web page transformations such as text…

Browsing Fatigue(also: Navigation Fatigue, Screen Reader Fatigue)

Physical and cognitive exhaustion experienced by users — particularly screen reader users and those with motor impairments — when navigating web content through repetitive, effortful interactions. For blind screen reader users, browsing fatigue results from excessive keyboard…

C2C Marketplace(also: Customer-to-Customer Marketplace, Peer-to-Peer Marketplace)

An online platform where individual consumers list goods or services for sale to other individual consumers, rather than selling through a business intermediary. Examples include eBay, Etsy, Mercari, Facebook Marketplace, Vinted, Depop, Gumtree, and Craigslist. C2C marketplaces…

CAPTCHA(also: Completely Automated Public Turing test to tell Computers and Humans Apart)

A challenge-response test used on websites to determine whether a user is human, typically requiring users to identify distorted text, select images, or solve puzzles. CAPTCHAs present significant accessibility barriers, particularly for users with visual impairments who cannot…

CSS Media Queries(also: Media Queries, Responsive Breakpoints)

A CSS feature that allows stylesheets to apply different rules based on characteristics of the user's device or viewport, such as screen width, resolution, color capability, or user preferences like reduced motion and high contrast. Media queries are foundational to responsive…

Captioning(also: Captions, Subtitles for the Deaf and Hard of Hearing, SDH)

The process of displaying synchronized text on screen that represents spoken dialogue, sound effects, and other audio information in video content. Unlike subtitles, captions are specifically designed for deaf and hard of hearing viewers and include non-speech sounds like [door…

Caret Browsing(also: Caret Navigation, Caret Browse Mode)

A browser navigation mode that places a movable text cursor (caret) directly in web page content, allowing users to navigate and select text using standard keyboard commands as if the page were a document in a text editor. Typically activated by pressing F7 in Firefox and…

Carousel(also: Image Carousel, Content Carousel, Slider Carousel)

A UI pattern that displays a rotating series of content items (images, cards, teasers) in a single area, typically navigated by swipe, arrows, or auto-advance. Carousels pose well-known accessibility risks: auto-rotation can violate WCAG 2.2.2 (Pause, Stop, Hide), items beyond…

Cell Navigation(also: Table Cell Navigation, Cell-by-Cell Navigation)

Cell navigation is a method of accessing tabular data non-visually by moving between individual cells using directional commands (up, down, left, right). Rather than reading a table linearly from top-to-bottom, cell navigation allows screen reader users to traverse the…

Cloud Accessibility(also: Cloud-Based Accessibility)

The use of cloud computing technologies to deliver, manage, and personalize accessibility features and assistive technologies. Cloud accessibility enables users to store their accessibility preferences remotely and have them applied automatically to any device or platform they…

Collaborative Accessibility Authoring(also: Collaborative Authoring, Crowdsourced Accessibility)

An approach to web accessibility in which a community of volunteers collaboratively creates, maintains, and shares accessibility fixes for websites they do not own or control. Rather than relying solely on site owners to make their content accessible, collaborative authoring…

Color Contrast(also: Colour Contrast, Contrast Ratio)

The difference in luminance between foreground text (or UI components) and their background, measured as a ratio. WCAG 2.1 requires a minimum contrast ratio of 4.5:1 for normal text and 3:1 for large text at Level AA, and 7:1 for normal text and 4.5:1 for large text at Level…

Compound Controls(also: Composite Widgets, Complex Controls)

User interface components that combine multiple interactive elements into a single logical control, such as a group of radio buttons, a set of checkboxes with a shared label, a combobox (combining a text input with a dropdown list), or a date picker with multiple fields.…

Compound Document(also: Compound Web Document, Multi-format Document)

A compound document is a single deliverable that seamlessly combines content in multiple formats — for example, an HTML page that embeds a Flash movie, an SVG graphic, an MathML expression, and a video player — each with its own internal document object model. Compound documents…

Conformance Evaluation(also: Conformance Assessment, Accessibility Conformance Testing)

The process of systematically assessing whether a website, application, or digital product meets the requirements of a specific accessibility standard, typically WCAG at a designated conformance level (A, AA, or AAA). Conformance evaluation typically combines automated testing…

Conformance Level(also: WCAG Level, Priority Level)

The three-tiered classification system used by WCAG to rank success criteria by their importance and impact on accessibility. Level A represents the minimum baseline — criteria that must be met or some users will be completely unable to access content. Level AA addresses the…

Content Adaptation(also: Content Transformation, Web Adaptation)

The process of modifying web content to make it more accessible or usable in different contexts, including for users with disabilities, users of assistive technologies, or users on constrained devices like mobile phones. Content adaptation encompasses techniques such as…

Content Extraction(also: Web Content Extraction, Text Extraction)

The process of separating meaningful content from the surrounding structural markup, navigation elements, and boilerplate text on a web page. For assistive technology users, content extraction is valuable because it allows them to focus on the substantive information on a page…

Content Personalization(also: Accessibility Personalization, Content Adaptation)

The practice of tailoring digital content presentation and interaction to match individual users' needs, preferences, and abilities. In accessibility, personalization goes beyond one-size-fits-all approaches by allowing users to specify how they prefer to receive information —…

Content Prioritization(also: Content Ranking, Element Prioritization)

The process of ranking or scoring web page elements by their relevance or importance to a user's task, enabling the interface to highlight critical content and de-emphasize less relevant material. Content prioritization can be achieved through AI-powered relevance scoring, where…

Content Re-Rendering(also: Content Transformation, Accessible Re-Rendering)

The process of taking content from one format or presentation and transforming it into a different format that is more accessible or usable for a specific audience. In accessibility, content re-rendering typically involves converting visually-encoded information (images, PDFs,…

Content Rearrangement(also: Information Rearrangement, Content Reordering, Page Restructuring)

An accessibility technique in which the content of a web page is automatically reorganised to present the most relevant information first, based on user context, intent, or navigational history. Content rearrangement addresses the sequential nature of screen reader output by…