Glossary

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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…

Chronic Obstructive Pulmonary Disease(also: COPD, Emphysema, Chronic Bronchitis)

A group of progressive lung diseases — including emphysema, chronic bronchitis, and non-reversible asthma — characterized by increasing breathlessness, cough, and reduced exercise tolerance. COPD affects approximately 10% of adults worldwide and is a leading cause of physical…

Chronic Pain

Persistent pain lasting longer than three months that may arise from an initial injury, ongoing illness, or without a clear physical cause. Chronic pain is a common experience among people with disabilities including Ehlers-Danlos Syndrome, fibromyalgia, and neuropathies. It can…

Chrononormativity(also: Temporal Normativity)

The way institutions impose normative temporal expectations—standardized timelines, schedules, and paces of development—that shape how bodies and lives are organized and evaluated. In assistive technology contexts, chrononormativity manifests through rigid institutional clocks…

Chunking

In cognitive science and human-computer interaction, chunking refers to the mental strategy of grouping individual items of information into larger, unified units (chunks) to reduce working memory load. Because human working memory can hold approximately four to seven items at a…

Circle of Friends(also: Circle of Support, Circles of Support)

Circle of Friends (or Circle of Support) is a facilitated social-inclusion intervention in which a person with a disability is surrounded by a small, intentional group of peers, family members, and supporters who commit to sustained involvement in their social life. The model…

Circuit Design(also: Electronic Circuit Design, Circuit Schematic Design)

The process of creating and representing electrical circuits that perform specific functions, using standard symbolic representations called schematics to show how components like resistors, capacitors, transistors, and switches are connected. Circuit design is foundational to…

Circumplex Model of Affect(also: Russell's Circumplex Model, Valence-Arousal Model)

A psychological framework that represents emotions along two continuous dimensions: valence (pleasure vs. displeasure) and arousal (activation vs. deactivation). Proposed by James Russell in 1980, the model maps all emotional states onto a circular space rather than treating…

Circumplex Model of Emotion(also: Russell Circumplex Model, Valence-Arousal Model, Circumplex Model of Affect)

A psychological model proposed by James Russell in 1980 that arranges emotional states in a two-dimensional plane defined by valence (pleasant vs unpleasant) and arousal (activated vs calm). The four quadrants correspond to high-arousal positive (e.g. excited, happy),…

Citation Form(also: Dictionary Form, Isolated Form)

The standard, isolated way a sign is produced when demonstrated independently, as typically shown in sign language dictionaries. In natural continuous signing, signs often appear differently from their citation form due to coarticulation, speed, regional variation, and…

Citational Justice(also: Citation Justice, Citational Politics)

The practice of consciously and equitably attributing knowledge to its sources, particularly uplifting contributions from marginalized scholars and communities whose work is often overlooked or appropriated. In accessibility research, citational justice means acknowledging…

Citizen Science(also: Community Science, Participatory Science)

Citizen science is a research approach that engages non-expert members of the public in collecting, processing, or analyzing scientific data, often through purpose-built interactive tools and platforms. In accessibility contexts, citizen science methods have been applied to…

Citizen Sensing(also: Citizen Sensor, Participatory Sensing)

A data collection approach in which members of the public use mobile devices or other tools to gather and report information about their environment, contributing to collective datasets that can inform decision-making. In accessibility contexts, citizen sensing enables people to…

Civic Participation(also: Civic Engagement)

Civic participation encompasses the activities through which individuals engage in the democratic process and public life, including voting, attending public meetings, contacting elected officials, and serving on boards or committees. For people with disabilities, barriers to…

Civic Technology(also: Civic Tech, Civic Hacking)

Technology developed by community members, advocacy groups, or volunteers to improve public services, increase government transparency, and address civic challenges. In accessibility, civic technology includes open-source tools and platforms built to monitor and improve the…

Civil Inattention

A social behavior theorized by sociologist Erving Goffman describing how strangers in public spaces acknowledge each other's presence through brief eye contact or a nod, then deliberately look away to respect personal boundaries. Civil inattention is a form of unfocused…

Clarifying Question(also: Clarifying Questions, Counter-Question)

A clarifying question is a follow-up query posed by a system or interlocutor to resolve ambiguity, fill missing context, or confirm intent before acting on a user's request. In conversational interfaces, clarifying questions are a core mechanism of mixed-initiative interaction:…

Classical Aesthetics(also: Classical Design Aesthetics)

A dimension of visual aesthetics in web design characterised by simplicity, clarity, orderliness, and visual cleanness. Classical aesthetic principles are rooted in early visual design traditions that prioritise clean layouts, minimal complexity, and clear organisation of…

Classifier(also: Classifier Predicate, Depicting Sign)

A type of sign language construction in which handshapes represent categories of objects or entities and are combined with movement and location to convey spatial information about position, movement, shape, or size. Classifiers are a core grammatical feature of sign languages…

Classifier Predicates(also: CL Predicates, Classifiers)

A type of sign language construction in which signers use their hands to represent the location, movement, size, shape, and spatial relationships of objects and people. Classifier predicates are among the most frequent and complex spatial phenomena in American Sign Language,…

Classifiers (Sign Language)(also: Classifier Predicates, CL (Sign Language))

Productive handshape-based constructions in sign languages that represent a class of referents — a vehicle, a flat object, a person walking, a small round object — and show their location, movement, shape, and interaction in signing space. Classifiers are a core part of ASL…

Clear Face Mask(also: Transparent Face Mask, Window Face Mask, See-Through Mask)

A face covering that incorporates a transparent panel over the mouth area, allowing deaf and hard of hearing people to lip-read and observe facial expressions during conversation. Clear face masks emerged as an important accessibility solution during the COVID-19 pandemic, when…

ClearSpeak

A set of rules for generating natural-sounding spoken descriptions of mathematical expressions, developed by ETS (Educational Testing Service). ClearSpeak uses conversational phrasing like "the fraction with numerator... and denominator..." rather than the more explicit…

Click-Time Distribution(also: Timing Profile, Click Precision)

A statistical model of when a switch user activates their switch relative to a target timing event, used to characterize the precision and consistency of a user's motor control. In the Nomon interface, the click-time distribution measures how accurately a user clicks when a…

Click-on-Lift(also: Lift-off Activation, Release Activation)

An interaction technique where a touch target is activated only when the user lifts their finger from the screen while still within the target area, rather than registering the action at the point of initial contact. This approach is particularly beneficial for users with hand…

Clicking Error(also: Click Slip, Selection Error)

An unintended mouse input that occurs during the clicking phase of target selection, distinct from errors in cursor positioning. Common clicking errors include slipping off the target (the cursor moves between button press and release), accidental clicks made while the mouse is…

Clinical Dementia Rating(also: CDR, CDR Scale)

The Clinical Dementia Rating (CDR) is a five-point staging scale used to characterise the severity of dementia, originally developed by Hughes and colleagues at Washington University in 1982. A clinician rates the person across six domains — memory, orientation, judgement and…

Clinical Reasoning(also: CR)

The cognitive and reflective process by which healthcare clinicians — particularly physical and occupational therapists — individualize care under patient and contextual uncertainty. Clinical reasoning blends analytic processes (hypothetico-deductive generation, pattern…

Clock Drawing Test(also: CDT)

The Clock Drawing Test (CDT) is a brief cognitive screening task in which a person is asked to draw a clock face, place the numbers, and set the hands to a specified time (commonly "ten past eleven"). Performance is scored on dimensions such as contour, number placement, and…

Clock Face Method(also: Clock Position Method, Clock Face Orientation, Clock Method)

A technique for describing the spatial position of objects relative to a person by using the positions on an analog clock face. For example, an item directly in front of a person is at 12 o'clock, to the right is at 3 o'clock, directly behind is at 6 o'clock, and to the left is…