Glossary

Search results

Caption Readability

The ease with which viewers can read and process caption text on screen, influenced by factors including font size, display duration, caption density, reading speed requirements, and competition with on-screen visual content. Caption readability is a core accessibility concern…

Caregiver Burnout(also: carer burnout, caregiver exhaustion)

A state of physical, emotional, and mental exhaustion that occurs when a caregiver does not get the support or respite they need, often resulting from the sustained demands of caring for a person with a chronic or progressive condition such as Alzheimer's disease. Symptoms…

Cascading Access Barriers(also: Compounding Barriers, Barrier Cascades)

A pattern where an initial accessibility barrier triggers a chain of subsequent barriers, each compounding the difficulty of the previous one. For example, missing a pharmacy notification (first barrier) leads to a medication gap (second barrier), which worsens executive…

Cause and Effect Software(also: Cause and Effect Games, Contingency Learning Software)

Simple interactive software designed for users with significant cognitive or motor disabilities, where any input (such as pressing a switch) produces an immediate sensory response (visual, auditory, or both). These programs help users understand the relationship between their…

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…

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…

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…

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:…

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…

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…

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…

Co-Presence(also: Copresence)

The sense of being together with another person in a shared space, whether physical or virtual, where individuals are aware of each other's presence and are "accessible, available, and subject to one another" (Goffman). Co-presence does not require active interaction—the mere…

Co-Regulation(also: Coregulation)

Co-regulation is the process by which one person helps another manage their emotional or physiological state, through presence, calming behaviours, modelling coping strategies, or environmental adjustment. It is well established in developmental psychology (parent helping a…

Cocktail Party Effect(also: Selective Auditory Attention)

The human ability to focus auditory attention on a single speaker or sound source while filtering out competing background noise or other simultaneous conversations. Named after the experience of following one conversation at a noisy party, this perceptual phenomenon has been…

Cognitive Accessibility Guidelines(also: COGA, Making Content Usable for People with Cognitive and Learning Disabilities)

W3C guidance for making web content accessible to people with cognitive and learning disabilities, including intellectual disabilities, autism, dementia, ADHD, dyslexia, and dyscalculia. Published as a W3C Working Draft, COGA provides design patterns for supporting users in…

Cognitive Aging(also: Age-Related Cognitive Decline)

Cognitive aging refers to the normal, gradual changes in cognitive function that occur as people grow older. These changes typically include declines in processing speed, working memory capacity, selective attention, and fluid intelligence (the ability to reason about novel…

Cognitive Artifact(also: Cognitive Artefact)

An artificial device — physical or digital — designed or appropriated to maintain, display, or operate on information in ways that support human cognitive performance. The term was codified by Don Norman to describe how objects like calendars, shopping lists, sticky notes,…

Cognitive Assessment(also: Neuropsychological assessment, Cognitive testing)

Structured evaluation of cognitive abilities — attention, memory, executive function, language, visuospatial processing, and more — using standardized tasks, questionnaires, or interactive assessments. Cognitive assessments support clinical diagnosis, screening for decline or…

Cognitive Assistance(also: Cognitive Aid, AI-Powered Assistance, Assisted Cognition)

Technology that uses artificial intelligence and machine learning to supplement or expand human cognitive and perceptual abilities. In accessibility contexts, cognitive assistance systems recognise people, objects, text, and environments and convey that information through…

Cognitive Decline(also: Cognitive Deterioration, Cognitive Aging)

A gradual reduction in cognitive abilities such as memory, attention, language, reasoning, and executive function that may occur as part of normal aging or as a symptom of neurological conditions such as mild cognitive impairment (MCI) or dementia. Cognitive decline exists on a…

Cognitive Demand(also: Cognitive Complexity, Cognitive Requirements)

The amount of mental effort, attention, and processing required to use a technology, interface, or system. High cognitive demand in assistive technology interfaces can prevent adoption by users with cognitive impairments, fatigue, or limited experience with technology.…

Cognitive Disability(also: Cognitive Impairment, Cognitive Disabilities)

A broad term encompassing conditions that affect cognitive processes such as memory, attention, perception, learning, language, and executive function. Cognitive disabilities include intellectual disabilities, traumatic brain injuries, neurodegenerative conditions, and…

Cognitive Disability(also: Cognitive Impairment, Intellectual and Cognitive Disability)

A broad category of disabilities affecting cognitive functions such as memory, attention, problem-solving, reading, language comprehension, and executive function. Cognitive disabilities can be developmental (such as Down Syndrome or Autism Spectrum Disorder), acquired (such as…

Cognitive Dysfunction(also: Cognitive Impairment, Cognitive Disability)

A broad term encompassing conditions that affect cognitive functions such as memory, attention, problem-solving, learning, language, and executive function. Cognitive dysfunction ranges from mild impairments (age-related memory decline, mild cognitive impairment) to major…

Cognitive Flexibility(also: Mental Flexibility, Set Shifting, Task Switching)

The executive function that allows a person to adapt their thinking and behavior in response to changing demands, switch between tasks, or consider multiple perspectives simultaneously. Cognitive flexibility is often challenged in autism, ADHD, and other neurodevelopmental…

Cognitive Interviewing

A qualitative research technique used to explore how survey respondents understand and mentally process assessment questions. Cognitive interviewing involves asking participants to think aloud as they interpret and answer questions, revealing misunderstandings, ambiguities, and…

Cognitive Load(also: Mental Load, Cognitive Demand)

The total amount of mental effort required to complete a task, encompassing the processing, storage, and management of information in working memory. Cognitive load theory distinguishes between intrinsic load (inherent task complexity), extraneous load (unnecessary complexity…

Cognitive Load Theory(also: CLT)

An instructional design theory proposing that learning is hindered when too much information is processed at once, overwhelming working memory. In sign language learning, cognitive load is particularly high because learners must simultaneously process and produce multiple…

Cognitive Map(also: Cognitive Mapping)

An internal mental representation of spatial relationships within an environment, formed through direct experience, exploration, or learning from maps and descriptions. Cognitive maps allow people to understand where they are relative to other locations, plan routes, and orient…

Cognitive Orthosis(also: Cognitive Prosthesis, Cognitive Assistive Device)

A technology-based device or system designed to compensate for cognitive deficits by supporting functions such as memory, planning, attention, and task sequencing. Analogous to a physical orthosis that supports a weakened limb, a cognitive orthosis augments impaired cognitive…

Cognitive Overload(also: Information Overload, Cognitive Load)

A state in which the amount of information or the complexity of a task exceeds a person's processing capacity, leading to reduced performance, comprehension, or decision-making ability. In accessibility contexts, blind users of visual assistance technologies may experience…

Cognitive Prosthesis(also: Cognitive Prosthetic, Digital Memory Aid)

A cognitive prosthesis is a technology-based system designed to supplement or replace cognitive functions that have been impaired due to conditions such as dementia, traumatic brain injury, or other neurological disorders. These systems can range from simple reminder apps to…

Cognitive Rehabilitation(also: Cognitive Rehab, Neuropsychological Rehabilitation)

A structured program of therapeutic activities designed to restore or compensate for cognitive functions impaired by brain injury, stroke, or other neurological conditions. Cognitive rehabilitation targets specific domains such as memory, attention, executive function, language,…

Cognitive Scaffolding(also: Scaffolded Support, Guided Task Support)

External supports or structures that help a person complete cognitive tasks they might not be able to manage independently. In education, scaffolding refers to temporary supports removed as competence grows; in accessibility, it often means persistent supports embedded in…

Cognitive Stimulation(also: Cognitive Stimulation Therapy, CST)

A structured programme of activities and discussions designed to engage and stimulate cognitive abilities — including memory, attention, language, and problem-solving — in people with mild to moderate dementia. Cognitive stimulation therapy (CST) is one of the few…

Cognitive Strategy Prompting(also: Cognitive Scaffolding, Strategy Prompting)

A design technique that provides cues or prompts within an interface to help users employ effective cognitive strategies for completing tasks, particularly benefiting users experiencing age-related cognitive decline or cognitive disabilities. Examples include framing tasks using…

Cognitive Theory of Multimedia Learning(also: CTML, multimedia learning theory)

A theory developed by Richard E. Mayer proposing that people learn more effectively from words and pictures together than from words alone, because the brain processes visual and auditory information through separate working-memory channels. CTML underpins design principles such…

Cognitive Training(also: Brain Training, Cognitive Remediation)

Structured programs or applications that use repeated practice on standardized tasks to improve specific cognitive functions such as working memory, attention, or processing speed. In accessibility contexts, cognitive training is particularly relevant for people with learning…

Cognitive Usability

The extent to which a system, interface, or information resource can be effectively used by people with varying cognitive abilities and processing styles. Cognitive usability goes beyond traditional usability measures (efficiency, effectiveness, satisfaction) to specifically…

Cognitive mapping(also: Mental mapping, Spatial cognitive map)

Cognitive mapping refers to the mental process by which individuals construct, store, recall, and apply internal representations of their spatial environment to navigate and orient themselves. These mental maps encode relationships between landmarks, routes, and regions, and…

Cognitive-Communication Needs(also: CCN, Cognitive-Communication Disorders)

Difficulties in communication that arise from underlying cognitive deficits in areas such as attention, memory, organization, problem-solving, and executive function, rather than from primary language impairments. Cognitive-communication needs commonly result from traumatic…

Cognitively Assistive Robot(also: CAR)

A category of socially assistive robot designed specifically to support people with cognitive impairments — most commonly mild cognitive impairment (MCI), dementia, traumatic brain injury, or learning disabilities — in everyday cognitive tasks such as remembering appointments,…

Coh-Metrix

A web-based tool developed at the University of Memphis that analyses text on more than a hundred measures of language, cohesion, and readability, including referential and semantic cohesion, lexical diversity, syntactic complexity, and latent semantic analysis. Coh-Metrix moves…

Coloured Overlay(also: Colored Overlay, Tinted Overlay, Reading Overlay)

A transparent coloured sheet placed over text or a digital colour filter applied to a screen to reduce visual stress and improve reading comfort for some people with dyslexia, Meares-Irlen syndrome, or other visual processing difficulties. Coloured overlays work by altering the…

Community Navigation(also: Community Travel, Community Mobility)

The ability to plan, initiate, and complete trips within one's community, including getting to transit points on time, using public transportation, and accessing services at destinations. For people with cognitive disabilities such as traumatic brain injury, community navigation…

Compassion Fatigue(also: secondary traumatic stress, empathy fatigue)

A state of emotional and physical exhaustion that results from the prolonged exposure to others' suffering, particularly in caregiving contexts. Unlike burnout, which develops gradually from chronic workplace stress, compassion fatigue can emerge rapidly and is characterized by…

Competency-Based Design(also: Competency-Based Approach)

An accessible design methodology that extends ability-based design by focusing on "competencies"—the representative practical skills people develop through participation in everyday activities, particularly mainstream technologies like social media. Unlike ability-based design,…

Complementary Cognition

A theory proposed by Taylor, Fernandes, and Wraight suggesting that the human species has adapted and evolved cognitively to complement each other through cognitive specializations and effective collaboration. Under this framework, different neurological profiles (including…

Computer Anxiety(also: Technophobia, Computer Phobia, Technology Anxiety)

Negative emotions and cognition processes — including fear, intimidation, apprehension, and hostility — evoked during actual or imagined interaction with computer-based technology. Computer Anxiety is a significant accessibility barrier particularly prevalent among older adults…