Glossary

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Re-narration(also: Web Re-narration, Content Re-narration)

The process of creating alternative versions of web content — such as translations, simplifications, audio descriptions, or culturally adapted media — to make it accessible to audiences who cannot effectively use the original. Unlike simple translation or metadata repair,…

Reaching Time(also: Navigation Time, Time to Target)

A usability metric measuring the time required for a user to navigate to a specific element on a web page. For blind users employing screen readers, reaching time is a key indicator of page navigability and efficiency, as it captures the cumulative cost of navigating through and…

Readability(also: Text Readability)

The ease with which a reader can read and understand written text. Readability encompasses both visual readability (typography, layout, color contrast, spacing) and linguistic readability (vocabulary complexity, sentence structure, text organization). In accessibility contexts,…

Reading Order(also: Logical Reading Order, Narration Order)

The sequence in which content is presented to assistive technology users, particularly screen reader users, when navigating a document or web page. For sighted users, the visual layout of a document (columns, sections, sidebars) implicitly suggests a reading flow, but screen…

Reading accessibility(also: Readable content, Text accessibility)

The design of written content and reading interfaces to be usable by people with diverse literacy levels, cognitive abilities, language backgrounds, and sensory capabilities. Reading accessibility encompasses plain language, text simplification, adjustable typography (font size,…

Relative Font Sizing(also: Relative Units, Scalable Typography, Flexible Font Sizes)

The practice of specifying text sizes using relative units (such as em, rem, or percentages) rather than absolute units (such as pixels or points), allowing text to scale when users adjust their browser or system font size settings. Relative font sizing is an important…

Relevance Scoring(also: Task Relevance Score, Content Relevance Rating)

The assignment of numerical scores to web page elements indicating how relevant they are to a user's specified task or goal. In systems like Task Mode, relevance scores typically range from 0 (completely irrelevant) to 100 (critical to the task), assigned by large language…

Relevance Threshold(also: Filtering Threshold, Display Threshold)

A user-adjustable cutoff value that determines which content elements are displayed or hidden based on their relevance scores. Elements scoring above the threshold are shown; those below are de-emphasized or removed. Relevance thresholds provide users with agency over how…

Renarration(also: Content Renarration, Web Renarration)

The process of re-telling, re-presenting, or re-styling existing web content to make it accessible to new audiences who face barriers the original content was not designed to address. Renarration goes beyond traditional accessibility remediation by enabling transformations that…

Retrofit Accessibility(also: Accessibility Retrofitting, Bolt-On Accessibility)

The practice of adding accessibility features to a product, system, or interface after it has already been designed and built for non-disabled users. Retrofit accessibility often results in suboptimal experiences because the fundamental interaction paradigms may be misaligned…

Rich Internet Application(also: RIA, Dynamic Web Application)

A web application that uses JavaScript and related technologies to provide interactive features, dynamic content updates, and sophisticated user interface widgets that approach the functionality of desktop applications. RIAs present significant accessibility challenges because…

Rich Text(also: Formatted Text, Styled Text)

Text content that includes visual formatting attributes beyond plain characters, such as font size, font family, color, bold, italic, underline, and other styling properties. On the web, rich text is created through HTML elements and CSS properties that give text visual emphasis…

Rich internet application(also: RIA)

A web application that uses client-side scripting (typically JavaScript) to provide dynamic, interactive functionality similar to desktop software, including features like drag-and-drop, real-time updates, and complex widgets. Rich internet applications present significant…

Role Attribute(also: ARIA Role, WAI Role)

An HTML attribute that defines the purpose or type of a user interface element, communicating its function to assistive technologies. Originally proposed as part of the XHTML namespace-based approach described by Gibson and Schwerdtfeger at IBM, the role attribute became a…

SERPA(also: Streamlined Evaluation and Reporting Process for Accessibility)

A programmer-centric methodology for conducting and reporting website accessibility evaluations, proposed by Law, Jacko, and Edwards in 2005. SERPA restructures the traditional accessibility evaluation process around the needs and constraints of the developers who must implement…

Scanning Navigation(also: Non-Visual Scanning, Auditory Scanning)

A non-visual navigation strategy in which a screen-reader or voice-browser user steps rapidly through a page one fragment at a time — line by line, item by item, or in fixed jumps (e.g. page-down keys) — listening just long enough to each fragment to detect an 'information…

Screen Reader Compatibility(also: Screen Reader Support, Screen Reader Accessible)

The degree to which a digital interface, website, application, or document can be effectively used with screen reader software. Screen reader compatibility requires proper semantic HTML structure, meaningful heading hierarchies, labeled form elements, appropriate ARIA…

Screen Reader User(also: SRU)

A person who uses screen reader software as their primary means of accessing digital content, typically someone who is blind or has low vision. Screen reader users interact with web content through audio output and keyboard or gesture-based navigation, experiencing pages…

Search Engine Optimization(also: SEO)

Search engine optimization (SEO) is the practice of improving a website's visibility and ranking in search engine results through techniques such as using descriptive page titles, meaningful headings, alt text for images, descriptive link text, and structured markup. Many SEO…

Section 508(also: 508 Compliance, Rehabilitation Act Section 508)

A provision of the United States Rehabilitation Act that requires federal agencies to make their electronic and information technology accessible to people with disabilities. Updated in 2017 (the "Section 508 Refresh"), the standards now incorporate WCAG 2.0 Level AA as the…

Semantic Accessibility

An approach to web accessibility that focuses on the predictability and consistency of user interface behavior, layout, and interaction patterns rather than the underlying code. Semantic accessibility ensures that similar elements appear in the same locations across pages, menus…

Semantic Accessibility Violation(also: Semantic A11y Violation)

An accessibility issue where HTML elements or attributes are technically present but fail to convey meaningful information to users with disabilities. Examples include alt text set to generic values like "image" instead of describing actual content, button labels that do not…

Semantic Bookmarking(also: Semantic Bookmark, Concept-Based Bookmarking)

A web navigation technique that associates saved page locations with meaningful conceptual labels from a domain ontology rather than with specific structural positions in the HTML code. Unlike traditional bookmarks that reference a URL or a position in the document's DOM tree…

Semantic Model(also: Semantic Tree, Semantic Web Model)

An abstract representation of a web page that captures the meaning and relationships of its content, rather than its raw HTML structure. Unlike the Document Object Model (DOM), which represents syntactic elements, a semantic model groups related elements into meaningful entities…

Semantic Partitioning(also: Web Page Partitioning, Content Partitioning)

A technique for automatically dividing a web page into semantically meaningful segments or blocks based on the structural and visual properties of its HTML content. Semantic partitioning analyzes the DOM tree to group related elements using spatial locality (items close together…

Semantic Structure(also: Semantic Representation)

Semantic structure refers to the meaningful organisation of content that captures the conceptual relationships between pieces of information, as distinct from the syntactic or visual presentation of that content. In web accessibility, semantic structure is critical because…

Semantic Transcoding(also: Annotation-driven Transcoding, Ontology-based Transcoding)

Semantic transcoding is the transformation of web content using explicit semantic information about the structure, role, or meaning of page elements — typically supplied through external annotations, ontologies, microformats, or ARIA. Because the transformation uses real…

Semi-Automatic Evaluation(also: Semi-Automated Testing, Guided Manual Evaluation)

An approach to accessibility evaluation that combines automated checks with human expert judgment. Semi-automatic tools run algorithmic tests to detect issues that can be identified programmatically — such as missing alt text or invalid ARIA attributes — and then guide the…

Sequential Navigation(also: Linear Navigation, Serial Navigation)

A method of accessing web content by moving through elements one at a time in the order they appear in the document structure, as opposed to visually scanning a page. Sequential navigation is the default mode for screen reader users, who use arrow keys or swipe gestures to move…

Shadow Page(also: Shadow Site, Text-Only Alternative)

A separate, simplified version of a web page created specifically to meet accessibility requirements, typically offering a text-only or reduced-complexity version of the original content. While shadow pages can address some accessibility barriers, they are generally considered a…

Single Page Application(also: SPA)

A web application architecture that dynamically updates page content in response to user interactions without requiring a full page reload, instead using JavaScript to modify the Document Object Model (DOM) and fetch data asynchronously. SPAs present unique accessibility…

Single-Page Application(also: SPA)

A web application that loads a single HTML document and dynamically updates its content through JavaScript without requiring full page reloads. SPAs use client-side routing and AJAX requests to fetch data and render new views within the same page, creating a more fluid,…

Skip Link(also: Skip Navigation Link, Skip Nav, Bypass Block)

A hidden or visible hyperlink placed at the beginning of a web page that allows keyboard and screen reader users to jump directly to the main content, bypassing repeated navigation elements. Skip links address WCAG Success Criterion 2.4.1 (Bypass Blocks) by providing a mechanism…

Skip Navigation(also: Skip Link, Skip Nav, Bypass Block)

A mechanism, typically an in-page anchor link placed at the very beginning of a web page, that allows keyboard and screen reader users to bypass repetitive content such as navigation menus and jump directly to the main content area. Skip navigation links are a WCAG 2.1 Level A…

Slide Deck Accessibility(also: Presentation Accessibility)

The practice of designing slide presentations to be usable by people with diverse disabilities, encompassing visual design choices (font size, colour contrast, background colour), structural elements (reading order, alt text for images, slide numbers), content considerations…

Social Media Accessibility

The practice of making social media platforms, content, and interactions accessible to people with disabilities. This encompasses platform-level features (alt text support, caption generation, screen reader compatibility), content creator practices (adding image descriptions,…

Social Networking Site(also: SNS, Social Network, Social Media Platform)

A social networking site (SNS) is an online platform that enables users to create profiles, connect with others, share content, and engage in social interactions. Examples include Facebook, Twitter/X, LinkedIn, Instagram, and WhatsApp. For accessibility, SNS design presents…

Social media accessibility(also: Accessible social media)

The design and implementation of social media platforms and content to be usable by people with disabilities, encompassing both platform-level accessibility (screen reader compatibility, keyboard navigation, captioned video) and content-level accessibility (alt text on images,…

Standards Harmonization(also: Standards Harmonisation, Accessibility Standards Alignment)

The effort to align web accessibility standards and guidelines across different jurisdictions, organizations, and markets to create a unified set of requirements that developers and content creators can follow. Without harmonization, fragmented accessibility standards — where…

State Abstraction(also: Page State Abstraction, State Grouping)

In automated web GUI testing, state abstraction is the process of grouping web pages that exhibit the same behaviour from a testing perspective into a single representative state. Effective state abstraction prevents testing tools from repeatedly exploring functionally identical…

Streaming Media(also: Streaming Audio, Streaming Video, Media Streaming)

Streaming media is audio or video content delivered to a user in a continuous flow from a server, played back as it arrives rather than waiting for a complete download. Because streaming content produces transient sound and images, and often begins auto-playing as soon as a page…

Success Criteria(also: Success Criterion, SC)

The testable statements within the Web Content Accessibility Guidelines (WCAG) that define specific requirements for making web content accessible. Each success criterion is assigned a conformance level (A, AA, or AAA) indicating its priority. Success criteria are…

Sufficient Techniques(also: Sufficient Advisory Techniques)

In the WCAG framework, sufficient techniques are documented methods for meeting a specific success criterion. If a content author correctly implements a sufficient technique, it is enough to satisfy the associated requirement. Multiple sufficient techniques may exist for a…

Syntactic Accessibility(also: Technical Accessibility)

The dimension of web accessibility concerned with the correctness of code sent to the browser and assistive technologies. Syntactic accessibility focuses on whether HTML markup, ARIA attributes, and other technical elements conform to standards so that content can be properly…

Tab Order(also: Focus Order, Navigation Order, Tabbing Order)

The sequence in which interactive elements receive keyboard focus when a user presses the Tab key to navigate through a web page or application. A logical tab order follows the visual layout and task workflow, allowing keyboard-only users to interact with content efficiently.…

Table Linearization(also: Table Serialization)

Table linearization is the process of converting a two-dimensional HTML table into a one-dimensional sequence of text for non-visual presentation. When a screen reader linearizes a table, it reads the content cell by cell, row by row, from top-left to bottom-right, stripping…

Table Navigation Mode(also: Table Navigation)

A screen reader feature that allows users to navigate within data tables by moving a virtual cursor cell-by-cell in two dimensions — by row and by column — rather than reading content linearly. Introduced by Ogane and Asakawa in 1998 and subsequently adopted by virtually all…

Table Reading Style(also: Table Reading Strategy, Table Browsing Style)

The particular way in which a reader accesses and processes the content of a data table, determined by the interaction between the table's structure, content, and the reader's intent. Common table reading styles include: by cell (random access to individual cells), by row…

Table accessibility(also: Accessible tables, Data table accessibility)

The practice of structuring data tables so they can be understood by assistive technology users. Accessible tables require proper markup that distinguishes header cells from data cells, establishes relationships between headers and the data they describe, provides captions or…

Table navigation(also: Table browsing, Grid navigation)

A set of screen reader commands that allow users to move between cells, rows, and columns within HTML tables, hearing row and column headers announced for context at each position. Effective table navigation enables non-visual users to understand spatial relationships in…