Glossary

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Adaptive Typography(also: Context-Aware Typography, Dynamic Typography)

The practice of adjusting text presentation - font size, weight, line spacing, character spacing, contrast, and colour - automatically or semi-automatically in response to the user's current needs and context. Adaptive typography goes beyond static accessibility settings by…

Alexia(also: Acquired Dyslexia, Word Blindness)

An acquired inability to read that results from brain damage, typically from stroke or traumatic brain injury, as distinct from developmental dyslexia which is present from childhood. People with alexia may lose the ability to recognize written words despite retaining other…

Aphasia

A language disorder that affects a person's ability to communicate, including difficulties with speaking, understanding speech, reading, and writing. Aphasia typically results from brain injury, most commonly stroke, and its severity and specific manifestations vary widely. In…

Automatic Text Simplification(also: ATS, Automated Simplification)

The use of computational methods to reduce the complexity of text while preserving its meaning, making it more accessible to readers with disabilities or limited literacy. Automatic text simplification includes lexical simplification (replacing difficult words with simpler…

Character Recognition

In the context of reading and cognitive accessibility, character recognition refers to the ability to correctly identify and distinguish individual letters and numbers. People with dyslexia often experience character recognition difficulties, confusing visually similar…

Character Spacing(also: Letter Spacing, Tracking)

The horizontal space between individual characters in a line of text. Research has shown that increasing character spacing significantly improves reading speed and accuracy for people with dyslexia. This effect is attributed to reduced visual crowding — the phenomenon where…

Cloze Test(also: Cloze Procedure, Cloze Deletion Test)

A reading comprehension assessment method in which words are systematically deleted from a text and the reader must fill in the missing words based on context. Developed by Wilson Taylor in 1953, cloze tests measure how well a reader understands the language patterns and meaning…

Concurrent Speech(also: Simultaneous Speech, Parallel Audio)

The presentation of multiple audio streams simultaneously, leveraging the human ability to selectively attend to one stream while monitoring others — known as the cocktail party effect. In accessibility research, concurrent speech has been explored as a way to help blind users…

Content Simplification(also: Content-Level Simplification)

Simplification approaches that modify the actual informational content of text, including summarization, removal of non-essential details, and restructuring of information presentation. Content simplification goes beyond lexical and syntactic simplification (which preserve all…

Decoding(also: Word Decoding, Phonetic Decoding)

The process of translating written symbols (letters or graphemes) into their corresponding sounds (phonemes) to recognize and read words. Decoding is a foundational reading skill described in the Simple View of Reading model, where reading comprehension equals the product of…

Digital Reading(also: Electronic Reading, Online Reading)

The act of reading text on digital devices including computers, tablets, smartphones, and e-readers. Digital reading differs from print reading in that it enables dynamic text modification, multimodal augmentation, and assistive technology integration that are not possible with…

Digital Ruler(also: Reading Ruler, Line Guide)

A digital tool that constrains the visible area of text to specific lines or paragraphs, reducing visual crowding and helping readers maintain focus on the current reading position. Digital rulers are analogous to physical reading rulers or overlays used by people with dyslexia.…

Dyslexia(also: Reading Disability, Developmental Dyslexia)

A neurologically-based learning disability that primarily affects the acquisition and processing of written language, manifesting as difficulties with reading, writing, spelling, and phonological processing. Dyslexia varies in severity and is estimated to affect 10-17% of the…

Dyslexia Screening(also: Dyslexia Assessment, Reading Disability Screening)

The process of identifying individuals who may be at risk for dyslexia, typically through standardized tests that assess reading fluency, phonological awareness, rapid naming, and other cognitive indicators associated with the condition. Traditional screening requires trained…

E-Book Accessibility(also: Electronic Book Accessibility, Digital Book Accessibility)

The design and implementation of electronic books to be usable by people with disabilities, including proper semantic structure, text resizing, reflowable content, alternative text for images, compatibility with screen readers, and customizable visual presentation. Despite the…

Easy Language(also: Easy-to-Read, Leichte Sprache, Easy Read)

A simplified form of written language designed to make information accessible to people with reading difficulties, including those with intellectual disabilities, prelingual hearing impairments, learning disabilities, low literacy, or limited proficiency in the language. Easy…

Emergent Literacy(also: Early Literacy, Pre-literacy)

The developmental process through which young children (typically birth through age 5) acquire foundational skills and concepts about reading and writing before formal instruction begins. For sighted children, picture books and illustrations play a crucial role by providing…

Fixation Problem(also: Reading Fixation Difficulty, Visual Fixation Issue)

A difficulty in maintaining stable visual focus on a specific point or line of text during reading. People with fixation problems may lose their place frequently, skip lines, or re-read the same passage unintentionally. This is a common challenge for dyslexic readers and can be…

Font Accessibility(also: Accessible Fonts, Dyslexia-Friendly Fonts)

The selection and design of typefaces to maximize readability for people with disabilities, particularly dyslexia and low vision. Research has evaluated various font properties for accessibility, finding that sans serif fonts, monospaced fonts, and fonts with distinct letter…

Functional Illiteracy(also: Low Literacy, Limited Literacy)

A condition in which a person has basic reading and writing skills but cannot effectively understand or use written text for everyday tasks such as reading instructions, filling out forms, or comprehending web content beyond simple sentences. UNESCO defines functional illiteracy…

Functional Literacy(also: Functional illiteracy)

The level of reading and writing skill needed to handle everyday tasks — filling out forms, reading medication instructions, understanding a utility bill, using a web service. Adults below this threshold are described as functionally illiterate, which in the United States is…

Jenga Format

Jenga format is a content transformation technique designed to enhance web page readability for non-native English readers. Developed by Chen-Hsiang Yu and Robert C. Miller at MIT, it restructures text presentation by visually grouping syntactic units within sentences, making…

Keyword Reading Strategy(also: Content Word Strategy)

The keyword reading strategy is a sentence-comprehension approach in which a reader focuses primarily on high-content words (nouns, verbs, adjectives, and adverbs) to derive the meaning of a sentence, while paying less attention to function words (determiners, prepositions, and…

Legibility

The visual clarity with which individual characters, words, and blocks of text can be distinguished and recognised. Legibility is influenced by font choice (sans-serif fonts are generally more legible on screen), font size (minimum 12px recommended for dyslexic users), letter…

Letter Reversal(also: Mirror Writing, Character Reversal)

A reading or writing difficulty where visually similar letters are confused or substituted for one another, such as swapping b for d, or p for q. Letter reversal is commonly associated with dyslexia and can significantly impact word recognition and reading comprehension. In…

Lexical Elaboration(also: Vocabulary Elaboration)

A text adaptation technique that makes content more accessible by adding explanatory information for complex or unfamiliar words, rather than replacing or removing them. Unlike text simplification, which rewrites content using simpler language, lexical elaboration preserves the…

Lexical Simplification(also: Word-Level Simplification)

A form of text simplification that focuses on replacing complex, uncommon, or technical words with simpler, more familiar alternatives. Lexical simplification is particularly relevant for readers with limited vocabulary, including people who are deaf or hard of hearing (for whom…

Literacy Development(also: Literacy Learning, Reading Development)

The process of acquiring reading and writing skills, from early phonological awareness through fluent reading comprehension. Literacy development is a key focus of reading support technology research, particularly for children with disabilities. Technologies supporting literacy…

Low Literacy(also: Limited Literacy, Functional Illiteracy)

A level of reading and writing ability that is below what is typically needed to function effectively in everyday situations requiring text comprehension. Low literacy may result from limited educational opportunities, learning disabilities, cognitive disabilities, or reading in…

MathSpeak(also: MathSpeak Rules)

A set of rules and conventions for verbally describing mathematical notation in a standardized, unambiguous way that can be understood by people who cannot see the visual representation of formulas. MathSpeak provides consistent patterns for reading mathematical expressions…

Meares-Irlen Syndrome(also: Irlen Syndrome, Visual Stress Syndrome, Scotopic Sensitivity Syndrome)

Meares-Irlen Syndrome is a perceptual processing disorder that affects how the brain processes visual information, causing symptoms of visual stress including pattern glare, perceptual distortions, eye strain, headaches, and discomfort when reading. Unlike dyslexia, it is not a…

Mixed Dyslexia

A subtype of dyslexia that combines features of both surface and phonological dyslexia, typically presenting as discourse-related difficulties including fixation issues and problems recognizing punctuation. Mixed dyslexia is generally considered more complex than either pure…

Multimodal Summarization(also: Multimodal Summary, MMS)

A technique for presenting information through multiple complementary formats — typically combining pictures, simplified text, and structural diagrams — to improve comprehension of complex content. Multimodal summarization is particularly valuable for accessibility because it…

Newsela

An educational content platform that publishes news articles in multiple professionally-edited versions simplified to different U.S. school reading levels, enabling teachers to assign the same story at grade-appropriate difficulty. Because Newsela pairs original articles with…

Non-Visual Reading(also: Audio Reading, Tactile Reading)

Methods of accessing written content without relying on visual perception, including braille reading, screen reader audio output, and text-to-speech technology. Non-visual reading is essential for blind users but presents unique challenges for navigation, skimming, and…

On-Demand Simplification(also: On-demand text simplification, User-initiated simplification)

An interaction pattern for Automatic Text Simplification reading-assistance tools in which the user explicitly requests a simpler version of a word, phrase, or sentence — typically via hover, click, or tap — rather than having the system pre-apply simplifications to the page…

Orthographic Depth(also: Orthographic Transparency, Spelling Transparency)

A measure of how consistently a written language maps between its spelling (graphemes) and pronunciation (phonemes). Shallow or transparent orthographies like Spanish, Finnish, and Italian have highly consistent letter-to-sound correspondences, while deep or opaque orthographies…

Orthography(also: Spelling System, Writing System)

The conventional spelling system of a language, including the rules and patterns that govern how sounds (phonemes) are represented by written symbols (graphemes). Languages vary in orthographic depth: shallow or transparent orthographies like Spanish and Italian have consistent…

Perceptual Span(also: Reading Span, Visual Span)

The area of text around a fixation point from which useful information can be extracted during reading. Research using eye-tracking has shown that skilled deaf readers have a larger perceptual span than hearing readers — up to 18 letter spaces compared to 14 for hearing readers…

Phoneme-Grapheme Mapping(also: Phoneme-Grapheme Correspondence, Alphabetic Principle)

The relationship between speech sounds (phonemes) and their written representations (graphemes), which is foundational to reading in alphabetic writing systems. Mastering phoneme-grapheme mapping — the alphabetic principle — is essential for fluent word recognition and a key…

Phonological Dyslexia

A subtype of dyslexia characterized by difficulty with sound-based word decoding, including problems with orthographically similar words (e.g., confusing "addition" and "audition"), number and letter recognition, and errors related to word substitutions, additions, or omissions.…

Polysemy(also: Polysemous Words)

The property of a word having multiple related meanings or senses. For example, the word "bank" can refer to a financial institution or the edge of a river. Polysemy creates particular challenges for text simplification and accessibility tools because choosing an appropriate…

Print Disabilities(also: Print Disability, Print Impairment)

A broad term encompassing any condition that prevents a person from effectively reading standard printed text. Print disabilities include blindness and low vision, but also extend to learning disabilities such as dyslexia, physical disabilities that prevent holding or…

Print Disability(also: Print Impairment, Print-related Disability, Print-related Disabilities)

A condition that prevents a person from effectively reading conventional printed material due to visual, physical, perceptual, developmental, cognitive, or learning disabilities. Print disabilities include blindness, low vision, dyslexia, and physical conditions that prevent…

Print Disability(also: Print Impairment)

A condition that prevents a person from effectively reading standard printed material. Print disabilities include blindness, low vision, dyslexia, and physical disabilities that make it difficult to hold or manipulate printed books. People with print disabilities rely on…

Rapid Serial Visual Presentation(also: RSVP)

A text display method in which words or short phrases are shown one at a time in a fixed location on screen in quick succession, eliminating the need for eye movements (saccades) between words. RSVP was first proposed in the 1950s for reading research and adapted for practical…

Read-Along(also: Read Along, Synchronised Highlighting, Karaoke-style Highlighting)

An accessibility pattern in which on-screen text is highlighted word-by-word or phrase-by-phrase in synchronisation with spoken audio. Used in children's reading apps, language-learning tools, accessible ebook formats (e.g., EPUB Media Overlays), and podcast players.…

Read-Aloud Technology(also: Read-Aloud Feature, Text Read-Aloud)

Technology that converts written text to spoken audio output, allowing users to listen to content rather than or in addition to reading it visually. Read-aloud technology differs from general text-to-speech in its focus on synchronized presentation — highlighting words or…

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,…

Readability(also: Text Readability)

The ease with which written text can be read and understood, determined by factors including vocabulary complexity, sentence length, grammatical structure, and text organisation. Readability is distinct from legibility (which concerns the visual clarity of individual characters…