Glossary

Search results

Acoustic Analysis(also: Acoustic Signal Analysis)

The computational examination of sound signals to extract measurable properties such as duration, fundamental frequency (pitch), intensity, spectral characteristics, and formant structure. In accessibility and clinical contexts, acoustic analysis is used to objectively assess…

Acoustic Event Detection(also: Sound Event Detection, Audio Event Detection, Sound Event Classification)

The automated process of identifying and classifying specific sounds within an audio stream, such as recognizing a phone ringing, door knocking, fire alarm, or speech from continuous environmental audio. Acoustic event detection systems use machine learning trained on labeled…

Acoustic Model(also: AM)

An acoustic model is the component of an automatic speech recognition (ASR) system that maps short segments of audio (typically 10–25 ms frames of spectral features) to the linguistic units that produced them — most commonly phonemes or sub-phonetic states. Classical acoustic…

Acoustic Phonetics

The branch of phonetics concerned with the physical properties of speech sounds, including their production, transmission, and perception as acoustic signals. Acoustic phonetics uses techniques such as spectral analysis, formant tracking, and landmark detection to characterize…

Acoustic Vehicle Alerting System(also: AVAS, Minimum sound requirement, Pedestrian warning sound)

A class of vehicle systems that emit artificial sound to alert pedestrians and other road users to the presence and movement of quiet vehicles — typically electric and hybrid vehicles at low speeds, where tire and aerodynamic noise are insufficient for detection. Regulatory…

Acquiescence Bias(also: Agreement Bias, Yea-Saying)

A response bias in which participants tend to agree with statements or respond affirmatively regardless of the actual content, often to be accommodating or to avoid conflict with the researcher. In accessibility research, acquiescence bias can be amplified among participants…

Acquiescence Bias(also: Agreement Bias, Yea-Saying)

A type of response bias where survey respondents tend to agree with statements regardless of their actual content. This "yea-saying" tendency can skew research results, particularly in accessibility studies where participants may feel inclined to provide positive feedback.…

Acquired Brain Injury(also: ABI)

Brain damage occurring after birth that is not hereditary, congenital, degenerative, or induced by birth trauma. ABI encompasses both traumatic brain injury (TBI) from external forces like falls or accidents, and non-traumatic causes such as stroke, anoxia, infection, or tumors.…

Acquired Disability(also: Adventitious Disability, Late-onset Disability)

A disability that develops after birth, typically due to illness, injury, or aging, as opposed to congenital disabilities present from birth. Common causes include stroke, traumatic brain injury, spinal cord injury, progressive diseases (such as multiple sclerosis or macular…

Action Research(also: Participatory Action Research, PAR)

A research methodology that combines investigation with practical action, involving iterative cycles of planning, acting, observing, and reflecting. In accessibility research, action research allows researchers to work alongside communities and organizations to simultaneously…

Action research(also: Participatory action research, PAR)

A research methodology that combines investigation with practical action, where researchers work collaboratively with community stakeholders to address real-world problems while simultaneously generating knowledge. Action research is cyclical — plan, act, observe, reflect — and…

ActionScript

A programming language used within Adobe Flash to create interactive content, animations, and web applications. ActionScript code was compiled into bytecode embedded in SWF files and executed by the Flash Player virtual machine. Because ActionScript ran inside the closed Flash…

Active Aging(also: Active Ageing, Healthy Aging, Successful Aging)

A policy framework and paradigm promoted by the World Health Organization that emphasizes maintaining physical activity, social engagement, and independence in later life to improve health outcomes and quality of life. While the concept has influenced health policy and…

Active Exploration(also: User-Directed Exploration)

An interaction paradigm in non-visual interfaces where users physically control their navigation through information, discovering content by directing a pointer, stylus, or finger across a surface or through a virtual space. In contrast to passive exploration, where the entire…

Active Learning(also: AL)

A machine learning paradigm in which the algorithm iteratively selects the most informative unlabeled data points to query a human annotator for labels, enabling effective model training with minimal labeled data. Active learning uses sampling strategies such as uncertainty…

Active Listening(also: Attentive Listening)

A communication technique where the listener fully concentrates on, understands, and responds to a speaker, demonstrating engagement through verbal and non-verbal feedback. Active listening behaviors include maintaining eye contact, nodding, providing verbal acknowledgments,…

Active Noise Cancellation(also: ANC, Active Noise Control)

A technique that reduces unwanted ambient sound by using microphones to capture incoming noise and electronically generating an inverted (anti-phase) audio signal that destructively interferes with it, lowering the perceived noise reaching the listener's ear. ANC is the core…

Active Perception(also: Active Sensing, Sensorimotor Exploration)

A view of perception in which the perceiver is not a passive receiver of stimuli but an active agent who moves, orients, and manipulates the environment to gather the sensory information needed for a task. In accessibility and sensory substitution research, active perception is…

Active Support

A person-centred model of support that enables people with intellectual disabilities, including those with severe and profound disabilities, to participate meaningfully in everyday activities and relationships. Active support involves providing graded levels of assistance — from…

Activities of Daily Living(also: ADLs, Daily Living Activities, ADL)

Routine tasks that people perform every day for self-care and independent functioning, including reading, cooking, grooming, dressing, and managing household items. For people with low vision, performing ADLs can be significantly impacted by reduced visual acuity, contrast…

Activities of daily living(also: ADLs, Daily living activities)

The fundamental self-care tasks that a person performs routinely each day, including feeding, bathing, dressing, grooming, toileting, and mobility. Originally proposed by Sidney Katz in the 1950s, ADLs are used in healthcare and occupational therapy as a measure of functional…

Activity Monitoring(also: Activity Recognition, Activity Tracking)

The use of sensors, algorithms, and computational models to automatically detect and track a person's actions and behaviours within an environment. In assistive technology contexts, activity monitoring enables smart home systems and cognitive orthoses to understand what a person…

Activity Pacing(also: Pacing, Energy pacing)

Activity pacing is a self-management strategy used by people with chronic conditions such as Multiple Sclerosis, fibromyalgia, and chronic fatigue syndrome to manage limited energy and prevent symptom exacerbation. It involves planning and distributing physical and cognitive…

Activity Prompting(also: Skill Prompting)

A structured approach to encouraging skill development through customized, playful prompts that guide individuals through specific activities. In the context of disability and education, activity prompting involves designing short, engaging tasks tailored to a person's current…

Activity Theory

A conceptual framework originating in Soviet psychology (Vygotsky, Leont'ev) and widely applied in HCI, which analyses human action as goal-directed activity mediated by tools, rules, community, and division of labour. Activity Theory provides a structured lens for studying how…

Activity Tracker(also: Fitness Tracker, Step Counter, Fitness Band)

An activity tracker is a wearable device or smartphone application that monitors and records physical activity data such as steps taken, distance traveled, calories burned, heart rate, and sleep patterns. In accessibility contexts, activity trackers raise important design…

Activity schedule(also: Visual schedule, Picture schedule)

A visual support tool that breaks down tasks or routines into sequential steps represented by photographs, pictograms, or text, enabling individuals with autism spectrum disorder, intellectual disability, or cognitive impairments to independently follow procedures without…

Acts of Assistance

A framework for designing human-machine interactions in cognitive assistive systems, drawing on speech acts theory from linguistics. Each act of assistance is a structured communication from the system to the user, defined by its message type (such as recall, indicate, or…

Ad Blocker(also: Adblocker, Content Blocker)

A browser extension or built-in feature that prevents advertisements, trackers, and other unwanted content from loading on web pages, typically by matching requests against blocklists such as EasyList or EasyPrivacy. Ad blockers can substantially improve accessibility by…

Ad-Hoc Customization(also: On-the-Fly Customization, Real-Time Adjustment)

Making customization changes during content consumption rather than configuring all settings beforehand. For ADHD video viewers, ad-hoc customization was preferred by 75% of participants because it allows viewers to react to distractions as they encounter them while gaining…

Adaptable system

A system that can be configured using prior knowledge before use, as opposed to an adaptive system which changes dynamically during use. In accessibility, adaptable systems allow users or administrators to set preferences in advance — for example, selecting a high contrast…

Adapted Curriculum(also: Adapted Computer Curriculum, Modified Curriculum, Curriculum Adaptation)

An adapted curriculum is an educational programme that has been modified to accommodate the learning needs, styles, and abilities of students with disabilities while maintaining the core learning objectives of the standard curriculum. Adaptations may include one-on-one tutoring…

Adaptive Assistive Technology(also: AAT, Adaptive AT)

Assistive technology that monitors a user's current and past performance and automatically adjusts its functionality to match their changing needs. Unlike static assistive technologies with fixed settings, adaptive systems continuously observe user behavior — such as typing…

Adaptive Behavior(also: Adaptive Skills, Adaptive Functioning)

The collection of conceptual, social, and practical skills that people learn and perform in everyday life. Conceptual skills include language, literacy, and self-direction; social skills encompass interpersonal abilities and social responsibility; practical skills involve…

Adaptive Boosting(also: AdaBoost)

A machine learning ensemble method that combines multiple weak classifiers to create a strong classifier, with each successive classifier focusing on the examples that previous classifiers misclassified. In computer vision and accessibility applications, AdaBoost is widely used…

Adaptive Cursor(also: Adaptive Navigation Cursor)

A cursor or navigation pointer whose speed, sensitivity, or behavior dynamically adjusts based on context such as the amount of content, the current navigation granularity, or user preferences. In text editing for blind users, an adaptive cursor might move more slowly through…

Adaptive Disclosure(also: On-Demand Disclosure, Progressive Disclosure for Accessibility)

An interface design pattern in which supplementary accessibility content — summaries, keyphrase previews, navigation maps, alternative descriptions — is revealed only when the user requests it rather than shown alongside the primary content at all times. Adaptive disclosure…

Adaptive Environment(also: Adaptive System, Responsive Environment)

A physical or digital space that automatically adjusts its properties and behaviours in response to the people within it. Adaptive environments use sensors, machine learning, and actuators to modify lighting, sound, temperature, display content, or interaction modes based on…

Adaptive Gameplay(also: Adaptive Difficulty, Dynamic Difficulty Adjustment)

A game design approach in which the system automatically adjusts difficulty, pacing, or content based on the player's real-time performance and behaviour. In accessibility and therapeutic contexts, adaptive gameplay is used to create personalized experiences for users with…

Adaptive Hypermedia(also: AH, Adaptive Hypermedia Systems, AHS)

Interactive systems that build a model of each user's goals, knowledge, preferences, and context, then use this model to automatically adapt the content, presentation, and navigation of hypermedia documents. Unlike static web pages that present the same interface to all users,…

Adaptive Instrument(also: Adapted Musical Instrument, Accessible Musical Instrument)

A musical instrument that has been specifically designed or modified to be playable by people with disabilities. Adaptive instruments may use alternative input methods such as touch sensors, breath control, eye tracking, or simplified physical interfaces to enable music creation…

Adaptive Interface(also: Adaptive UI, Self-Adapting Interface)

A user interface that automatically adjusts its layout, content, or behavior based on user context, abilities, preferences, or device constraints without requiring explicit user configuration. Adaptive interfaces in accessibility research have included systems that modify visual…

Adaptive Interface(also: Adaptive User Interface, Self-Adapting Interface)

A user interface that automatically modifies its presentation, behaviour, or content based on detected user characteristics, capabilities, preferences, or environmental conditions. In accessibility, adaptive interfaces can respond to changes in a user's sensory, motor, or…

Adaptive Multi-Rate Codec(also: AMR, AMR Codec, AMR-NB)

A family of audio codecs used in mobile telephony to encode voice for transmission. AMR-NB (narrowband) operates at 300-3,400 Hz with bit rates from 4.75-12.2 kbps, while AMR-WB (wideband, also called HD Voice) extends to 50-7,000 Hz at 6.6-23.85 kbps. AMR-WB is adopted by 3GPP…

Adaptive Musical Instrument(also: Accessible Musical Instrument, Adapted Instrument)

A musical instrument that has been modified or purpose-built to enable people with disabilities to play music. Adaptive musical instruments may use alternative input methods such as head movement, breath control, eye tracking, or switch access to replace or supplement…

Adaptive Navigation(also: Adaptive Navigation Support)

A technique in which a system dynamically modifies the presentation of navigational elements (such as links, menus, or breadcrumbs) based on user characteristics, behaviour, or context. In accessibility applications, adaptive navigation can reorder, annotate, hide, or highlight…

Adaptive Optics(also: AO)

A technology that measures and corrects optical distortions in real time, originally developed for astronomical telescopes and now applied in ophthalmology and vision science. Adaptive optics systems use a wavefront sensor to detect aberrations and a deformable mirror or other…

Adaptive Rendering(also: Content Adaptation, Dynamic Rendering)

The process of automatically modifying how web content is presented based on a user's needs, preferences, or device capabilities. Adaptive rendering can involve transformations such as adjusting layout, reformatting text, replacing images with alternative representations,…

Adaptive Seating(also: Specialized Seating, Custom Seating)

Wheelchair seating systems and positioning devices customized to meet an individual's specific postural needs, providing support for the trunk, head, and limbs to enable optimal function and comfort. Adaptive seating is often essential for people with cerebral palsy or other…

Adaptive Sports(also: Para Sports, Disability Sports, Adapted Sports)

Sports that have been modified or specifically designed to enable participation by people with disabilities, including modifications to rules, equipment, or playing environments. Adaptive sports range from wheelchair versions of mainstream sports (basketball, rugby, tennis) to…