Glossary

Search results

Above the Fold(also: Above-the-fold, First Screen Content)

Content that is visible on a web page without requiring the user to scroll. The term originates from newspaper publishing where important headlines appeared above the physical fold of the paper. In digital accessibility and usability, above-the-fold placement is significant…

Access Friction(also: Accessibility Friction)

The effort, frustration, or barriers encountered when attempting to access technology, services, or environments. Access friction can range from minor inconveniences to complete exclusion and may result from poorly designed interfaces, lack of accommodations, bureaucratic…

Accessibility Feature Discovery(also: Feature Discoverability, Accessibility Awareness)

The process by which users learn about, find, and activate accessibility features available on their devices or in software. Research shows that the vast majority of users — particularly older adults — are unaware of built-in accessibility features on their smartphones and…

Accessibility-in-Use(also: Accessibility in Use)

A concept describing how well accessibility metrics predict the actual effects that real accessibility problems will have on the quality of interaction as perceived by real users when interacting with real pages for achieving real goals. Unlike traditional conformance testing…

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

A user interface that automatically modifies its behavior, presentation, or content based on observed user characteristics, interaction patterns, or context of use. In accessibility, adaptive interfaces can detect when a user is experiencing difficulty — through patterns like…

Affective Congruency

The degree to which a system's sensory outputs, interactions, and feedback align emotionally with the user's current affective state and the emotional meaning the user attaches to the experience. Distinct from perceptual congruency, affective congruency concerns whether the…

Affective Engagement(also: Emotional Engagement)

The emotional connection and investment a user develops with a task, activity, or technology. In accessibility and therapeutic contexts, affective engagement goes beyond usability to encompass motivation, enjoyment, and emotional safety. Research shows that affective engagement…

Age-Friendly Design(also: Design for Aging, Senior-Friendly Design)

An approach to designing products, services, and environments that accommodates the needs and capabilities of older adults, including those experiencing age-related changes in vision, hearing, cognition, and motor skills. Age-friendly design overlaps significantly with…

Age-friendly design(also: Senior-friendly design, Gerontechnology design)

A design approach that specifically addresses the perceptual, cognitive, and motor changes associated with aging, including larger fonts, simplified interfaces, reduced jargon, higher contrast, and minimized demands on working memory and perceptual speed. Research shows that…

Alarm Fatigue(also: Alert Fatigue, Notification Fatigue)

A phenomenon in which an individual becomes desensitised to alarms, alerts, or notifications due to their excessive frequency, repetitive nature, or lack of meaningful context, leading the person to ignore, snooze, or dismiss them. In healthcare and medication management, alarm…

Anchoring Effect(also: Anchoring Bias, Cognitive Anchoring)

A cognitive bias in which people rely too heavily on an initial piece of information (the "anchor") when making subsequent decisions or judgements. In the context of digital accessibility, the anchoring effect has been documented in alt text authoring, where content authors who…

Assistive Technology Abandonment(also: AT Abandonment, Technology Discontinuance)

The phenomenon of users with disabilities ceasing to use an assistive technology device or system after initial adoption. Research identifies several predictors of abandonment, including failure to consider user opinions during design, lack of training, poor device performance,…

Audience Modelling(also: Audience Modeling, User Modelling)

The practice of characterizing and formally describing distinct groups of users and their interaction characteristics to inform the design and evaluation of web interfaces. In accessibility, audience modelling involves identifying the specific abilities, disabilities, devices,…

Auditory Interface(also: Audio Interface, Aural Interface, Non-Visual Interface)

A user interface that conveys information and accepts input primarily through sound rather than visual displays. Auditory interfaces range from simple screen reader output to complex auditory environments using spatial audio, earcons, speech synthesis, and sonification. In…

Auditory Satisfaction

The overall positive emotional and cognitive response users experience after engaging with audio content, encompassing contentment with auditory features, narration style, and technical quality. In accessible media research, auditory satisfaction is measured across dimensions…

Automation Confusion

A phenomenon, well documented in human–automation literature and observed in partially automated video games, in which the user struggles to distinguish the outcomes of their own actions from those performed autonomously by a software agent. In shared-control gaming this can…

Avatar(also: Virtual Self, Digital Representation, Self-Avatar)

A graphical representation of a user within a virtual environment or digital platform. Avatars can range from simple icons to fully customizable 3D virtual humans that mirror user movements. In accessibility research, avatar customization has been shown to increase engagement…

Browsing Fatigue(also: Navigation Fatigue, Screen Reader Fatigue)

Physical and cognitive exhaustion experienced by users — particularly screen reader users and those with motor impairments — when navigating web content through repetitive, effortful interactions. For blind screen reader users, browsing fatigue results from excessive keyboard…

Calibrated Trust(also: Appropriate Reliance, Trust Calibration)

An HCI and human-factors concept, articulated by Lee and See, describing the alignment between a user's trust in an automated or AI system and the system's actual capability in a given context: trusting the system when it is reliable and being skeptical when it is not. Designing…

Calibration-Free Interface(also: Zero-Shot Interface, Plug-and-Play Interface, Cross-User Model)

An input system that works for a new user without any per-user training or calibration data, typically by relying on models trained on large multi-user datasets that capture enough physiological and behavioural variation to generalise. Voice assistants and mixed-reality hand…

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…

Communicability

A quality property of interactive systems proposed by Semiotic Engineering theory, referring to the system's ability to effectively and efficiently convey to users the designer's communicative intentions, logic, and underlying interaction principles. High communicability means…

Comprehensibility(also: Comprehension, Intelligibility)

The degree to which users can understand and retain the key elements of content, including events, characters, actions, settings, and narrative progression. In audio-described media for visually impaired users, comprehensibility measures how effectively the audio presentation…

Conceptual Model(also: Mental Model)

A user's internal understanding of how a system works, including what actions are possible, what the current state is, and what the consequences of actions will be. Conceptual models are critical in accessibility because users who cannot build an accurate mental representation…

Confidence Indicator(also: Confidence Score, Uncertainty Indicator)

An interface element that communicates how certain an AI or automated system is about a given output, helping users decide how much to trust the result. In accessibility tools for blind and low-vision users, confidence indicators are especially important because users cannot…

Confirmation Message(also: Positive Feedback, On-track Feedback, Progress Confirmation)

A system message that reassures users they are performing a task correctly or are on the right path, as opposed to only providing error messages or corrective instructions. In assistive technology and cognitive accessibility, confirmation messages have been shown to be…

Context of Use(also: Use Context, Usage Context)

The combination of users, tasks, equipment (hardware, software, and materials), and the physical and social environments in which a product or service is used. In accessibility, context of use is a critical consideration because the same website may present different barriers…

Coping Strategies(also: Coping Tactics, Workaround Strategies)

The techniques and approaches that users with disabilities develop to navigate around accessibility barriers they encounter on the web and in digital interfaces. Expert screen reader users, for example, employ strategies such as using element lists, virtual search, heading…

Coping Strategy(also: Coping Behavior, Adaptive Strategy)

A behavioral pattern or workaround that users with disabilities employ when encountering inaccessible digital content or interfaces. Coping strategies emerge when technology fails to meet accessibility needs, forcing users to develop alternative approaches such as skipping…

Customization(also: User Customization)

Customization is the practice of allowing users to adapt a system's behaviour, output, or presentation to match their individual goals, preferences, and context. In accessibility, customization is essential because disability is heterogeneous: users of screen readers, AI…

Decision Confidence

A reframing of accessibility as whether a user can judge product suitability, transaction risk, and information trustworthiness well enough to act independently — introduced by Ryskeldiev et al. (2026) in the context of blind and low-vision e-commerce. Where WCAG conformance…

Design Fixation(also: Fixation Effect)

A cognitive phenomenon in the design process where exposure to existing examples or initial solutions constrains creative thinking, causing designers to replicate or only minimally modify those examples rather than exploring original alternatives. In AI-assisted design, fixation…

Digital Self-Efficacy(also: Technology Self-Efficacy, Computer Self-Efficacy)

An individual's belief in their ability to effectively use digital technologies to accomplish tasks. Digital self-efficacy influences how people approach technology challenges, persist through difficulties, and recover from errors. For people with progressive cognitive…

E-Commerce Accessibility(also: Accessible E-Commerce, Online Shopping Accessibility)

The degree to which online shopping experiences — product discovery, evaluation, checkout, fulfilment, customer support, and (on peer-to-peer platforms) selling — are usable by people with disabilities, particularly blind and low-vision (BLV) users who depend on screen readers,…

Ecological Validity

In user experience research, the degree to which a mediated experience feels natural, realistic, and believable—as if it could occur in a real-world context. In immersion measurement frameworks like the ITC Sense of Presence Inventory, ecological validity is a subscale alongside…

Embodied Experience(also: Embodied Interaction, Embodiment (UX))

The dimension of user experience that arises from the body's sensory and kinaesthetic encounter with a system or environment — motion, vibration, balance, proprioception, ambient sound, and felt pace — rather than from explicit information channels. In autonomous transport,…

Emotional Engagement(also: Affective Engagement)

The degree to which a user connects emotionally with content, characters, and narrative, experiencing feelings such as excitement, tension, empathy, humor, or sadness in response to the media. In accessibility research on audio-described webtoons, emotional engagement is a…

End-User Customization(also: User Customization, Personalisation)

The ability for users to modify the presentation or behaviour of a digital interface according to their individual preferences and needs. In accessibility, end-user customization is particularly important because there is no universal profile for many disability groups — people…

Escapism

The use of entertainment, fantasy, or immersive experiences to temporarily disconnect from real-world concerns, limitations, or stressors. In VR accessibility research, escapism is a significant motivator for disabled users, who may value VR as an opportunity to experience…

Execution Gap(also: Gulf of Execution)

From Don Norman's model of human-computer interaction, the distance between a user's goals and the physical actions required to achieve them using a given system. A system with a wide execution gap forces users to translate what they want into technical commands, parameters, or…

Experiential Accessibility(also: Experience-Centric Accessibility)

An approach to accessibility that goes beyond removing barriers to ensure disabled people can have equitable, meaningful experiences with technology—not just functional access. In the context of experiential technologies like virtual reality or games, this means designing for…

Expert User(also: Advanced User, Power User)

A user who has substantial experience with a system and has internalised its structure, commands, and idioms. Expert users typically prefer direct, efficient interaction — keyboard shortcuts, command-line syntax, scripting, and customised workflows — over step-by-step menus.…

Extrinsic Motivation

Extrinsic motivation refers to engaging in an activity to achieve external rewards, avoid punishment, or meet external expectations rather than for inherent enjoyment. In accessibility and technology design, extrinsic motivators include gamification elements like badges, points,…

Faceted Navigation(also: Faceted Search, Faceted Browsing, Faceted Filtering)

A navigation technique that allows users to filter and explore content along multiple dimensions or categories simultaneously, such as by topic, sentiment, date, or rating. In accessibility contexts, faceted navigation can significantly improve the efficiency of information…

Flow(also: Flow state, Optimal experience, Being in the zone)

A psychological state of complete absorption in an activity, characterized by focused concentration, loss of self-consciousness, altered sense of time, and intrinsic enjoyment. Coined by psychologist Mihaly Csikszentmihalyi, flow occurs when a person's skills are well-matched to…

Flow State(also: Flow, Optimal Experience, Being in the Zone)

A mental state of complete immersion and focused engagement in an activity, characterized by a balance between challenge level and skill level. In accessible design, achieving flow state is important for learning systems and games because it maximizes engagement without causing…

Flow Theory(also: Flow State, Flow)

A psychological theory proposed by Mihaly Csikszentmihalyi describing the state of deep immersion and intrinsic enjoyment that occurs when a person is fully engaged in an activity whose challenge level closely matches their skill level. Flow is characterized by clear goals,…