Glossary

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Cerebellar Ataxia(also: Ataxic Dysarthria)

A neurological condition caused by damage to the cerebellum that affects coordination, balance, and motor control. In speech, cerebellar ataxia produces ataxic dysarthria characterized by irregular speech rhythm, explosive or scanning speech patterns, imprecise consonants, and…

Cerebral Palsy(also: CP)

A group of permanent movement disorders that appear in early childhood, caused by abnormal development or damage to the parts of the brain that control movement, balance, and posture. Cerebral palsy affects approximately 1 million people in the United States, with symptoms…

Cerebral Palsy(also: CP)

A group of permanent movement disorders caused by abnormal development or damage to the parts of the brain that control movement, balance, and posture. Cerebral palsy affects approximately 1 in 345 children and can range from mild to severe, potentially affecting fine motor…

Cerebral Visual Impairment(also: CVI, Cortical Visual Impairment, Brain-Based Visual Impairment)

A form of visual impairment caused by damage to or dysfunction in the brain's visual processing centres, rather than problems with the eyes themselves. CVI is the leading cause of childhood vision impairment in developed countries and is projected to become a leading cause of…

Cerebral Visual Impairment(also: CVI, Cortical Visual Impairment)

Cerebral visual impairment (CVI) is an umbrella term for visual deficits resulting from damage to the brain rather than the eyes. It affects visual perception, including visual acuity, cortical image processing, and pattern recognition. CVI is often associated with additional…

Certified Deaf Interpreter(also: CDI)

A Deaf or Hard-of-hearing individual who has obtained professional certification from the Registry of Interpreters for the Deaf (RID) to provide interpreting, translation, and transliteration services. CDIs work in tandem with hearing interpreters or independently, bringing…

Chain-of-Thought(also: CoT, Chain of Thought Reasoning, Step-by-Step Reasoning)

Chain-of-thought is a prompting and model-design technique in which a large language model produces its intermediate reasoning steps before giving a final answer. Modern reasoning models (e.g., OpenAI o-series, Claude thinking modes) expose chain-of-thought as visible internal…

Chain-of-Thought Prompting(also: CoT Prompting)

A technique for improving the reasoning capabilities of large language models by instructing them to break down complex tasks into intermediate reasoning steps before producing a final answer. In accessibility applications, chain-of-thought prompting is used to improve the…

Chairable(also: Chair-based interface, Wheelchair-integrated technology)

A design concept for input and output devices that are integrated directly into a wheelchair frame, enabling users to interact with assistive technology without requiring a separate smartphone, wearable device, or other external hardware. Chairables might include thin flexible…

Chairable Technology(also: Chairable Input, Chairable Devices)

Input devices and interactive technologies designed to integrate with the form of a wheelchair, analogous to how wearable technology fits with an individual's clothing. Chairable technology recognises that power wheelchair users spend most of their waking hours in their chairs…

Chairable computing(also: Chairable input, Wheelchair-integrated computing)

A design paradigm in which input devices and computing interfaces are integrated into the form factor of a wheelchair — particularly armrests, trays, and frames — analogous to how wearable computing fits with clothing. Chairable devices are always within reach, require no setup…

Challenge-Point Framework

A motor-learning theory proposed by Guadagnoli and Lee (2004) which holds that learning is optimised when the difficulty of a task is appropriately matched to the learner's current skill level. Tasks that are too easy provide little information to learn from, while tasks that…

Challenging Behavior(also: Problem Behavior, Behaviors of Concern)

Actions by individuals with intellectual or developmental disabilities that pose risks to themselves or others, or significantly interfere with daily activities and learning. In the context of autism, challenging behaviors are often classified into categories such as…

ChamBadge(also: Chambadge)

A wearable accessible cell phone device developed as part of the Talking Braille ubiquitous computing system for indoor wayfinding. The ChamBadge combines a cell phone with a bone-conduction headset, an infrared transceiver, and wireless networking capabilities, worn behind the…

Change Blindness(also: Changeblindness, Inattentional Blindness)

Change blindness is a perceptual phenomenon in which observers fail to notice changes to a visual scene when the change coincides with a visual disruption such as an eye movement, blink, or brief occlusion. In accessibility contexts, change blindness is particularly relevant for…

Change Management(also: Organizational Change Management)

A structured approach for transitioning individuals, teams, and organizations from a current state to a desired future state. In accessibility, change management addresses the human and organizational factors that determine whether accessibility improvements are adopted and…

Character Error Rate(also: CER)

A metric for evaluating automatic speech recognition (ASR) and optical character recognition (OCR) accuracy, measuring the minimum number of character-level edits (insertions, deletions, substitutions) needed to transform the system output into the reference text, divided by the…

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…

Charge-Coupled Device(also: CCD)

An electronic light sensor used in cameras and scanners that converts light into electrical signals. CCDs capture images by accumulating electric charge in proportion to the intensity of light hitting each pixel. In accessibility applications, CCD sensors are used in optical…

Charity Model of Disability(also: Charity Model)

A framework that views people with disabilities as helpless victims who are dependent on the goodwill and benevolence of others. Under this model, disability is treated as a tragedy requiring charitable intervention, positioning disabled people as passive recipients of aid…

Chart Question Answering(also: Chart QA, ChartQA, Visual Question Answering for Charts)

The task of answering natural-language questions about a data visualization, typically a chart provided as an image or structured specification. A chart question answering system must identify the chart type, extract the underlying data, interpret axes and legends, and answer…

Chartability(also: Chartability Heuristics)

A set of heuristics for assessing the accessibility of data visualizations, developed by Frank Elavsky and the Dataviz Accessibility group. Chartability provides a systematic framework for evaluating whether charts, graphs, maps, and other data visualizations are accessible to…

ChatGPT(also: GPT, OpenAI ChatGPT)

ChatGPT is a conversational generative AI assistant developed by OpenAI, based on the GPT family of large language models. Users interact via a text chat interface and, in newer versions, through voice, image, and file upload. ChatGPT is widely used as an accessibility tool —…

ChatGPT Accessibility(also: GenAI Accessibility)

The degree to which ChatGPT and similar generative AI interfaces can be effectively used by people with disabilities, including compatibility with screen readers, keyboard navigation, and non-visual interaction patterns. Research with teachers with vision impairments in India…

Chatbot(also: Virtual Assistant, Conversational Agent, Dialog System)

A software application that uses text or speech to conduct conversations with users, simulating human-like dialogue to provide information, perform tasks, or guide users through processes. In accessibility, chatbots and conversational user interfaces present both opportunities…

Chatbot Accessibility(also: Accessible Chatbot Design, CUI Accessibility)

The practice of designing chatbots and conversational user interfaces (CUIs) to be usable by people with disabilities. Chatbot accessibility presents unique challenges compared to traditional web accessibility because CUIs involve dynamic, dialogue-based interactions rather than…

Checklist Accessibility(also: Checklist Conformism, Checklist Compliance)

A critique of accessibility practice in which organisations treat accessibility as a set of discrete technical checks to be ticked off (alt text present, ARIA labels declared, contrast ratios met) rather than as ongoing engagement with disabled users. Checklist accessibility can…

Checkpoint(also: WCAG Checkpoint, Success Criterion, Accessibility Checkpoint)

A checkpoint is a specific, testable accessibility requirement in a set of guidelines — for example, 'provide a text equivalent for every non-text element' is WCAG 1.0 checkpoint 1.1. The term is strongly associated with WCAG 1.0, which was organised into 65 numbered checkpoints…

Chemical Markup Language(also: CML)

An XML-based markup language for representing chemical information including molecular structures, reactions, spectra, and other chemical data in a machine-readable format. CML encodes atoms, bonds, and molecular properties in a structured text format that can be processed by…

Chernoff Faces(also: Chernoff's Faces)

A visualisation technique introduced by Herman Chernoff in 1973 that represents multivariate data by mapping each data variable to a facial feature — eye size, eye spacing, nose length, mouth curvature, face shape, and so on — producing one cartoon face per data sample. The idea…

Chest-Mounted Camera(also: Body-Worn Camera, Torso Camera)

A wearable camera mounted on the user's chest or torso to capture a first-person perspective of activities. In accessibility research, chest-mounted cameras are used to record BLV users' daily activities like cooking for dataset collection and to provide visual input for…

Chiari Malformation(also: Arnold-Chiari Malformation)

A structural condition in which brain tissue extends into the spinal canal, which can cause a range of neurological symptoms including headaches, balance issues, and vision problems such as blurred or double vision, nystagmus, and reduced contrast sensitivity. Digital…

Child Agency

Child agency is a child's capacity to initiate, shape, direct, and sustain activities - including play, conversation, and social interaction - rather than passively accepting adult or peer control. In accessibility research for children, agency is recognised as relational and…

Child Behavior Checklist(also: CBCL, K-CBCL)

A standardised parent-report assessment tool used to evaluate behavioural and emotional problems in children aged 6-18. It measures internalising problems (anxiety, withdrawal, somatic complaints) and externalising problems (aggression, rule-breaking). The CBCL is widely used in…

Childhood apraxia of speech(also: CAS, Developmental verbal dyspraxia, DVD)

A motor speech disorder in which the brain has difficulty planning and coordinating the precise movements of the tongue, lips, jaw, and palate needed for intelligible speech. Unlike other speech disorders caused by muscle weakness, CAS involves impaired motor programming — the…

Children with Vision Impairments(also: CVI, Students with Visual Impairments, Blind Students)

Children and young people who are blind or have low vision, requiring adapted educational approaches including Braille instruction, tactile learning materials, audio resources, and assistive technology. India has the world's largest population of children with vision…

Chinese Natural Sign Language(also: CNSL)

Chinese Natural Sign Language (CNSL) is the language used by roughly twenty million Deaf and Hard-of-Hearing people in China. Unlike Chinese Sign Language (CSL) — an artificial, school-and-broadcast system that follows spoken Mandarin word order — CNSL has its own spatial-visual…

Chinese Sign Language(also: CSL, Zhongguo Shouyu)

Chinese Sign Language (CSL) is the primary sign language used by the deaf community in mainland China. Like all sign languages, CSL has its own grammar, syntax, and vocabulary that are distinct from spoken and written Mandarin Chinese. CSL is used by an estimated 20 million deaf…

Choice-Making(also: Choice Board, Aided Choice)

A structured communication and learning strategy in which an individual is presented with two or more options and supported to make a selection, often using pictures, objects, or symbols. Choice-making is a foundational skill in autism education and therapy, serving multiple…

Chord Entry(also: Chording, Chord Input, Chordal Input)

A method of text input where multiple keys are pressed simultaneously to produce a single character, rather than pressing keys sequentially. In braille keyboards such as the Perkins Brailler, chord entry involves pressing combinations of six keys at once to represent different…

Chording Keyboard(also: Chord Keyboard, Chorded Keyboard, Chording Input)

A text input device that generates characters by pressing multiple keys or moving multiple inputs simultaneously rather than pressing individual keys sequentially as on a standard keyboard. Similar to how piano chords combine multiple notes, each character is produced by a…

Choropleth Map(also: Thematic Map, Shaded Map)

A type of thematic map in which geographic areas are shaded or patterned in proportion to a statistical variable, such as population density, income level, or unemployment rate. Darker or more intense colors typically represent higher values. Choropleth maps are widely used by…

Chroma Key(also: Green Screen, Blue Screen, Chroma Keying)

A video-post-production technique in which a solid, uniformly coloured background (often green or blue) is replaced with another image, video, or transparency using colour-matching software. In accessibility work, chroma key is most often encountered in the production of…

Chrome Web Store(also: CWS)

Google's official marketplace for Chrome browser extensions, themes, and applications, organised into 18 categories including Accessibility, Privacy & Security, Productivity, and Shopping. Extensions submitted to the store undergo automated review and, in some cases, manual…

ChromeVox(also: ChromeVox Classic)

ChromeVox is an open-source screen reader developed by Google, built as a Chrome browser extension and serving as the default screen reader for Chrome OS (Chromebooks). Unlike traditional screen readers that rely on operating system accessibility APIs, ChromeVox communicates…

Chronic Condition(also: Chronic Health Condition, Long-Term Condition)

A health condition that persists over time, typically lasting a year or more and requiring ongoing medical attention or limiting activities of daily living. Chronic conditions include both chronic illnesses (such as diabetes or multiple sclerosis) and other lasting health states…

Chronic Disease(also: Chronic Condition, Long-term Condition)

A chronic disease is a health condition that persists for a year or more, requires ongoing medical attention, and limits daily activities. Examples include diabetes, heart disease, asthma, hypertension, arthritis, and dementia. Chronic diseases affect approximately 60% of adults…

Chronic Fatigue Syndrome(also: CFS, ME/CFS, Myalgic Encephalomyelitis)

A complex, long-term condition characterised by profound fatigue not relieved by rest, post-exertional malaise, cognitive difficulties ("brain fog"), and often sleep disturbance and pain. CFS is an invisible and episodic disability: symptoms and capacity fluctuate day-to-day,…

Chronic Illness(also: Chronic Condition, Long-Term Illness)

Health conditions that persist for an extended period, typically more than three months, and may require ongoing management but do not necessarily have a cure. Examples include diabetes, fibromyalgia, multiple sclerosis, and chronic fatigue syndrome. People with chronic…