Glossary

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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…

Clock Position(also: Clock face position, Clock orientation)

A method of conveying direction to a person who is blind by mapping the 12-hour clock face onto the user's immediate surroundings, where 12 o'clock is directly ahead, 3 o'clock is to the right, 6 o'clock is behind, and 9 o'clock is to the left. Clock-position directions (e.g.,…

Clock Technique(also: Clock Method, Clock Face Direction System)

An orientation method used in mobility training for blind and visually impaired people in which directions are communicated using the positions on an analogue clock face. The user imagines standing at the centre of a clock with 12 o'clock directly ahead, 3 o'clock to the right,…

Clock-Based Directional Audio(also: Clock-Face Audio Cueing, Clock Position Audio)

A spatial orientation system that communicates direction to users by referencing positions on a clock face (e.g., "3 o'clock" for right, "12 o'clock" for directly ahead), often combined with distance estimates. In accessible VR and gaming contexts, clock-based directional audio…

Close Reading

A qualitative analytic method in which researchers slowly and attentively examine a text, image, or artifact, documenting observable features and interpretive responses in detail. In accessibility research, close reading is used to surface patterns in artifacts such as alt text,…

Closed Captioning(also: CC, Closed Captions)

Text displayed on screen that represents dialogue, sound effects, music, and other audio information in video content, which viewers can toggle on or off. Unlike open captions, closed captions are a separate data stream that can be enabled or disabled by the viewer. Closed…

Closed Captioning(also: CC, Closed Captions)

Text displayed on a screen that transcribes spoken dialogue, identifies speakers, and describes relevant sound effects in video content. Unlike open captions which are permanently embedded in the video, closed captions can be toggled on or off by the viewer. Closed captioning is…

Closed Captions(also: CC)

Captions that can be turned on or off by the viewer, as opposed to open captions which are permanently embedded in the video. Closed captions typically include not just dialogue but also descriptions of relevant non-speech audio like music, sound effects, and speaker…

Closed Interpreting(also: Closed Sign Language Interpreting)

A proposed accessibility feature for video content where a sign language interpreter video can be toggled on or off and displayed alongside the main video, analogous to closed captions for text. Unlike embedded "open" interpreters that are permanently part of the video, closed…

Closed-Loop Adaptation(also: Closed-Loop System, Adaptive Loop)

A system design approach where real-time feedback from sensors or user behavior is continuously monitored and used to automatically adjust the system's response. In accessibility technology, closed-loop adaptation enables interfaces to respond dynamically to users' physiological…

Closed-Loop Control(also: Feedback Control)

A control strategy in which a system continuously measures the current state, compares it to a desired reference, and adjusts its output to minimize the error. Contrasted with open-loop control, which acts without sensing outcomes. In assistive wearables, closed-loop control is…

Closed-loop Interaction(also: Closed-Loop Feedback, Perform-Assess-Adjust Cycle)

An interaction pattern in which a system continuously observes the user's action, evaluates it, and returns immediate feedback that shapes the next attempt, producing an iterative perform-assess-adjust cycle. Closed-loop interaction contrasts with open-loop designs that present…

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…

Cloud-Based Assistive Technology(also: Assistive Technology as a Service, ATaaS, Cloud AT)

An approach to delivering assistive technology through cloud computing, where personalised accessibility software configurations, preferences, and tools are stored remotely and delivered on demand to any device via the internet. This model addresses the portability problem:…

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…

Clue and Reasoning Prompting(also: CARP, Clue-and-Reasoning Prompting)

A prompt engineering strategy for large language models that instructs the model to first identify textual clues (keywords, phrases, contextual information) in the input and then perform diagnostic reasoning based on those clues before producing a classification output.…

Clustering Algorithm(also: Cluster Analysis, Unsupervised Clustering, K-means)

A clustering algorithm is an unsupervised machine-learning technique that groups similar data points together based on a distance or similarity measure, without needing pre-labelled training data. Common algorithms include K-means, PAM (Partitioning Around Medoids), CLARA…

Clutching(also: Clutch Mechanism, Clutch Gesture)

In gesture- and motion-based input systems, a mechanism that lets the user temporarily disengage the recogniser so that everyday, non-communicative movements — reaching, adjusting posture, gesturing socially — do not trigger false activations. Named after the mechanical clutch…

Co-Adaptive Design(also: Co-Adaptive Interaction, Mutual Adaptation)

A design approach where both the technology and its users adapt to each other over time through ongoing interaction. Rather than designing a fixed system that users must learn to operate, co-adaptive design creates flexible tools that evolve through use as users develop personal…

Co-Authorship(also: Co-authoring, AI Co-Authorship)

In AI-mediated writing and communication, the shared production of text between a human user and an AI system, where neither party fully owns the resulting output. Co-authorship raises questions about credit, intent, authenticity, and accountability, and these become especially…

Co-Creative(also: Co-Creativity, Co-Creative AI)

A framing of human-AI collaboration in which the AI acts as a creative partner rather than a tool or a replacement — contributing ideas, drafts, or alternatives that the human writer, artist, or designer evaluates, accepts, rejects, or revises. Co-creative systems typically…

Co-Cultural Theory(also: Co-Cultural Communication Theory)

A communication theory developed by Mark Orbe that examines how members of marginalized or underrepresented groups communicate within dominant societal structures. The theory identifies the Deaf community as a subordinate group within a hearing-dominated society and analyzes how…