Glossary

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Single-case experimental design(also: SCED, N-of-1 design, ABAB design)

A rigorous research methodology that evaluates intervention effects by systematically alternating between baseline and treatment conditions within individual participants, using each person as their own control. Common variants include AB, ABA, ABAB, and multiple-baseline…

Singular Value Decomposition(also: SVD)

A mathematical technique that decomposes a matrix into three component matrices, used to reduce high-dimensional data to its most important features while preserving essential relationships. In accessibility research, SVD is a core component of Latent Semantic Analysis and has…

Sip-and-Puff(also: Sip and Puff Switch, Pneumatic Switch)

An assistive technology input device that detects air pressure changes from a user sipping (inhaling) or puffing (exhaling) through a straw or tube to generate control signals. Sip-and-puff systems are primarily used by people with severe motor impairments, particularly those…

Situated Knowledge(also: Situated Knowledges)

A concept from feminist epistemology, developed by Donna Haraway, holding that all knowledge is produced from particular social, bodily, and historical positions rather than from a neutral, objective standpoint. In disability studies and accessibility research, situated…

Situated Learning

A theory of learning, associated with Jean Lave and Etienne Wenger, which holds that knowledge is not primarily abstract information transferred between minds but an embodied practice acquired through doing things in a real social context with other practitioners. In…

Situated Learning Theory(also: Situated Cognition)

An educational theory proposing that learning is most effective when it occurs in authentic contexts naturally tied to the activity, culture, and environment where the knowledge will be used. In sign language education, situated learning supports embedding ASL practice in…

Situated Play Design(also: SPD)

Situated Play Design is a design approach developed by Altarriba Bertran and colleagues that treats play as something emergent from a specific social, physical, and cultural setting rather than something to be engineered into a generic product. It combines ethnographic…

Situated action(also: Situated cognition, Situated practice)

A theoretical framework from sociology and HCI holding that human actions and decisions are fundamentally shaped by the specific social, material, and temporal context in which they occur, rather than being pre-planned or rule-following. In explainable AI design, situated action…

Situation Awareness(also: SA, Situational Awareness)

The perception and understanding of one's current environment, including the identification of relevant elements, comprehension of their meaning, and projection of their future status. In accessibility and assistive technology contexts, situation awareness refers to systems that…

Situational Awareness(also: Environmental Awareness)

The perception and understanding of elements in one's environment, including the ability to detect events, comprehend their significance, and anticipate what may happen next. For deaf and hard of hearing individuals, situational awareness is significantly affected by limited…

Situational Disability(also: Situational Impairment, Contextual Disability)

A temporary limitation in ability caused by environmental or situational factors rather than a medical condition. Examples include being unable to hear audio in a noisy environment, having limited dexterity while carrying items, or experiencing reduced vision in bright sunlight.…

Situational Disability(also: Situational Impairment, Situational Limitation, SIID)

A temporary reduction in ability caused by a person's environment or context rather than a permanent condition. Examples include difficulty reading a screen in bright sunlight (visual), being unable to listen to audio in a noisy environment (auditory), or having limited…

Situational Disability(also: Situational Impairment, Contextual Disability)

A temporary limitation in ability caused by environmental circumstances rather than a permanent condition. Examples include being unable to read a screen in bright sunlight (visual), not hearing audio in a noisy environment (auditory), being unable to use two hands while…

Situational Impairment(also: Situational Disability, Situationally-Induced Impairment)

A temporary reduction in a person's ability to interact with technology caused by their environment or context rather than a permanent condition. Examples include using a phone in bright sunlight (visual), operating a device while carrying groceries (motor), or trying to hear…

Situational Judgment Test(also: SJT, Situational Judgement Test)

A hiring assessment that presents candidates with hypothetical workplace scenarios and asks them to select the "best" and "worst" responses from a predefined multiple-choice list. SJTs assume a single correct behaviour per scenario, which can systematically disadvantage…

Situational Limitations(also: Situational Impairments, Contextual Limitations)

Temporary constraints on a user's ability to interact with technology due to their environment, device, or circumstances rather than a permanent disability. Examples include using a mobile phone in bright sunlight (limiting screen visibility), being in a noisy environment…

Situational Trust(also: Situational Trust in Automation)

A context-sensitive form of trust in an automated system that varies moment-to-moment based on perceived system performance, environment, and the user's own capacity to intervene. Unlike dispositional or generalised trust, situational trust is recalibrated as conditions change —…

Situational Visual Impairment(also: SVI, Situational Visual Impairments)

A temporary reduction in a person's effective vision or reading performance caused by the environment or context rather than by a medical condition. Common examples include trying to read a phone screen in bright sunlight, while walking or on a moving vehicle, in low light, or…

Situationally Induced Impairment(also: SIID, Situational Impairment, Situational Disability)

A temporary functional limitation caused by environmental or contextual factors rather than a permanent health condition or disability. Examples include difficulty using a phone while walking (reduced motor accuracy), inability to hear audio in a noisy environment, or screen…

Situationally-Induced Impairments and Disabilities(also: SIIDs, Situationally Induced Impairments and Disabilities, Situation-Induced Disabilities)

An accessibility framework, introduced by Sears et al., that describes how everyday environments and tasks can temporarily impose the same kinds of barriers on non-disabled users that permanent impairments create for disabled users. Examples include reading a phone in bright sun…

Skeleton Tracking(also: skeletal tracking, body tracking, pose estimation)

Technology that detects and tracks the positions of human body joints (such as head, shoulders, elbows, hands) in real-time from camera or depth sensor data. In accessibility applications, skeleton tracking enables gesture-based interfaces, sign language recognition, and…

Skeuomorphic Design(also: Skeuomorphism)

A design approach in which digital interface elements are made to resemble their real-world physical counterparts in appearance and behavior. For example, a digital notepad might have lined paper texture and a spiral binding, or a file folder icon might open with a tab-dragging…

Skill-Based Matchmaking(also: SBMM)

An online matchmaking approach that attempts to pair competitors of similar demonstrated skill so that matches are appropriately challenging. SBMM is the dominant industry response to ability imbalances in competitive multiplayer video games, but it depends on a dense population…

Skilled Vision(also: Vernacular Vision, Professional Vision)

Skilled vision is a concept from visual culture and anthropology that describes the process of learning to see and interpret visual information in specialized ways within a particular community of practice. Originally applied to professional fields (e.g., radiologists learning…

Skimming(also: Scanning, Speed Reading, Content Skimming)

Skimming is a speed-reading technique in which a reader quickly glances through text to get the general idea or gist without reading every word. Sighted readers skim by scanning headlines, bold text, first sentences of paragraphs, and visually prominent content. For blind and…

Skimming Interface(also: Skim Reading Tool, Speed Reading Interface)

A technology interface designed to help users quickly scan and identify relevant content within a text without reading every word. Skimming interfaces have been particularly explored for blind and low vision users who use screen readers, where linear reading can be extremely…

Skin Conductance(also: SC, Skin Conductance Response, SCR)

A measure of the electrical conductance of the skin, which increases with sweat gland activity. Skin conductance is commonly used as an index of emotional arousal or sympathetic nervous system activation. In accessibility contexts, wearable sensors measuring skin conductance can…

Skin Stretch(also: Tangential Skin Stretch)

A haptic feedback technique that conveys directional or magnitude information by laterally stretching the skin at the fingertip, palm, or other contact point rather than by vibration or kinesthetic force on a joint. Skin stretch engages slowly adapting tactile mechanoreceptors…

Skin Stretch Display(also: Skin Stretch, Lateral Skin Deformation Display, STReSS)

A type of haptic display technology that produces tactile feedback by laterally stretching the skin of the user's fingertip, rather than using raised pins or vibration. Skin stretch displays typically use arrays of small actuators (such as piezoelectric bending motors) that…

Skip Link(also: Skip Navigation Link, Skip Nav, Bypass Block)

A hidden or visible hyperlink placed at the beginning of a web page that allows keyboard and screen reader users to jump directly to the main content, bypassing repeated navigation elements. Skip links address WCAG Success Criterion 2.4.1 (Bypass Blocks) by providing a mechanism…

Skip Navigation(also: Skip Link, Skip Nav, Bypass Block)

A mechanism, typically an in-page anchor link placed at the very beginning of a web page, that allows keyboard and screen reader users to bypass repetitive content such as navigation menus and jump directly to the main content area. Skip navigation links are a WCAG 2.1 Level A…

Slide Accessibility(also: Presentation Accessibility, Accessible Presentations, Accessible Slides)

The practice of designing and delivering slide presentations so they can be fully accessed and understood by people with disabilities, particularly screen reader users. Key requirements include setting proper reading orders for slide elements, providing alt-text for images and…

Slide Deck Accessibility(also: Presentation Accessibility)

The practice of designing slide presentations to be usable by people with diverse disabilities, encompassing visual design choices (font size, colour contrast, background colour), structural elements (reading order, alt text for images, slide numbers), content considerations…

Slide Rule

A pioneering touch-based screen reader interaction technique for mobile devices, developed by Kane et al. in 2008, that makes touchscreen content accessible to blind users through finger-driven exploration. Slide Rule allows users to scan items by dragging a finger across the…

Slider(also: Content Slider, Swipe Slider)

A UI pattern where content items are arranged horizontally and navigated by swiping or tapping arrow controls, exposing one or a few items at a time. Unlike carousels, sliders typically do not auto-advance. Accessibility concerns overlap with carousels: keyboard access,…

Slips(also: Slip Errors, Selection Slips)

Errors that occur when a user intends to click on a target but the cursor moves off the target before the mouse button is released, resulting in a missed selection. Slips are particularly common among older adults and people with motor impairments due to difficulties with fine…

Sloping Hearing Loss(also: High-frequency Hearing Loss, Sloping SNHL)

Sloping hearing loss is a common audiogram shape in which hearing thresholds are relatively preserved at low frequencies and progressively worse at higher frequencies, producing a downward slope on the audiogram. It is the typical presentation of age-related hearing loss…

Slow Cortical Potential(also: SCP, Slow Cortical Potentials)

Gradual voltage shifts in the electrical activity of the brain, occurring over periods of several hundred milliseconds to several seconds. Slow cortical potentials reflect changes in the overall excitability level of cortical neural networks — negative shifts indicate increased…

Slow Design

Slow design is a design philosophy that emphasizes thoughtful, reflective, and sustained engagement over efficiency and speed. Inspired by the slow food movement, it values deeper contemplation, longer development timelines, and meaningful user experiences. In museum and gallery…

SlowKeys(also: Slow Keys)

An accessibility feature that requires a key to be held down for a specified minimum duration before the keypress is accepted by the system. SlowKeys helps users with motor disabilities who frequently make accidental keystrokes by brushing against keys or pressing keys…

Small Fiber Neuropathy(also: SFN)

A condition involving damage to small somatic and autonomic nerve fibers, resulting in burning pain, sensory disturbances, and autonomic dysfunction. SFN can make everyday tasks that involve gripping, holding, or fine motor control painful and difficult. Assistive devices that…

Small Language Model(also: SLM)

A language model, typically ranging from tens of millions to a few billion parameters, designed to run on consumer or edge devices rather than in centralized cloud data centers. Small language models sacrifice some of the broad general knowledge of frontier large language models…

Small Multiples

A series of similar graphics or charts arranged in a grid or sequence, each showing a different frame, condition, or time point, used to illustrate change or comparison. In tactile graphics, small multiples are the traditional method of representing movement or temporal change —…

Small-n Experimental Design(also: Small-sample Design, Single-case Design)

Small-n (or single-case) experimental design is a family of research methodologies aimed at drawing rigorous causal conclusions from very few — sometimes just one — participants. The approaches include ABA reversal, multiple baseline designs, alternating treatments, and changing…

Smart Cane(also: Electronic Cane, Intelligent Cane)

An enhanced version of the traditional white cane that incorporates electronic sensors — typically ultrasonic or infrared — to detect obstacles beyond the range of physical contact, providing haptic or auditory feedback to the user. Smart canes can detect obstacles at waist or…

Smart City(also: Intelligent City, Smart City Accessibility)

An urban area that uses information and communication technologies (ICT) to improve the quality and efficiency of city services, infrastructure, and governance. In accessibility contexts, smart city technologies — including real-time public transit tracking, connected…

Smart Display(also: Smart Screen, Voice Assistant Display)

A voice-controlled device that combines a smart speaker with a built-in touchscreen, enabling multimodal interaction through voice commands, visual output, and touch input. Examples include the Amazon Echo Show and Google Nest Hub. Smart displays offer accessibility advantages…

Smart Environment(also: Intelligent Environment, Smart Space)

A physical space equipped with sensors, computing devices, and networked systems that can monitor conditions, infer context, and respond to the activities and needs of occupants. Smart environments aim to improve quality of life by automating tasks and providing contextual…

Smart Glasses(also: AR Glasses, Assistive Smart Glasses)

Smart glasses are head-mounted wearable devices that incorporate cameras, microphones, speakers, and computing capabilities into an eyeglass form factor. For people who are blind or have low vision, smart glasses can use computer vision and AI to provide real-time information…

Smart Home(also: Home Automation, Connected Home)

A residence equipped with networked devices and systems that can be monitored and controlled remotely or automatically, including lighting, heating, security, and entertainment systems. Smart home technology has significant accessibility potential — enabling people with motor…