Glossary

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Semantic Navigation(also: Semantic Navigation Framework, Structured Navigation)

An approach to organizing digital content into a meaningful hierarchical structure that users can navigate through logically ordered elements rather than by spatial position. In the context of accessible data visualizations, semantic navigation frameworks arrange chart…

Semantic Network(also: Semantic Web, Associative Network)

A knowledge representation structure in which concepts are represented as nodes and the relationships between them as links or edges. In accessibility and AAC contexts, semantic networks model how words and concepts are associated in the human mind, enabling vocabulary tools to…

Semantic Transcoding(also: Annotation-driven Transcoding, Ontology-based Transcoding)

Semantic transcoding is the transformation of web content using explicit semantic information about the structure, role, or meaning of page elements — typically supplied through external annotations, ontologies, microformats, or ARIA. Because the transformation uses real…

Sensorimotor Rhythm(also: SMR, Sensorimotor Cortical Rhythm)

Oscillatory electrical brain activity recorded over the sensorimotor cortex, the brain region responsible for planning and executing voluntary movements. Sensorimotor rhythms include mu rhythms (8-12 Hz) and beta rhythms (18-26 Hz), which change in amplitude when a person…

Sensory Aid(also: Sensory Assistive Device)

Assistive technologies that translate sensory inputs into alternative modalities to support people with sensory disabilities in the workplace and daily life. Examples include screen readers (visual to auditory), captioning systems (auditory to visual), haptic feedback devices…

Sensory Substitution(also: Cross-Modal Substitution)

The use of one sensory modality to convey information typically perceived through another. For example, converting visual information into tactile or auditory signals for blind users, or representing sound through vibration for deaf users. Sensory substitution is a fundamental…

Sensory augmentation(also: Sensory substitution system, Sensory augmentation technology)

Technology that provides information from one sensory channel through an alternative modality accessible to the user, such as converting visual scenes to audio descriptions for blind users or translating sounds to visual or haptic alerts for deaf users. AI-powered sensory…

Sensory substitution(also: Cross-modal substitution, Sensory Substitution Device, SSD)

The technique of conveying information normally received through one sense via a different sensory channel, such as converting audio cues into vibrotactile feedback or visual signals. Sensory substitution is a foundational concept in assistive technology, enabling people who are…

Sentence Prediction(also: Phrase Prediction, Utterance Prediction)

An AAC text entry acceleration technique that suggests complete sentences or phrases based on what the user has begun typing. Unlike word prediction which completes individual words, sentence prediction allows users to select entire utterances with a single action, dramatically…

Sentence-Level Bookmark(also: In-Page Bookmark, Content Bookmark)

A type of bookmark that marks a specific position within a web page's content, rather than simply saving the page's URL. Sentence-level bookmarks allow users — particularly those using screen readers or speech-based interfaces — to jump directly to a known location within a long…

Sequential Navigation(also: Linear Navigation, Serial Navigation)

A method of accessing web content by moving through elements one at a time in the order they appear in the document structure, as opposed to visually scanning a page. Sequential navigation is the default mode for screen reader users, who use arrow keys or swipe gestures to move…

Serious Game(also: Serious Games, Applied Game)

A game designed for a primary purpose beyond entertainment, such as education, training, health intervention, or cognitive rehabilitation. In accessibility and healthcare contexts, serious games are used to support people with conditions like ADHD by targeting specific cognitive…

Serious Games(also: Applied Games, Games for Health, Therapeutic Games)

Games designed with a primary purpose beyond entertainment, such as education, training, therapy, or rehabilitation. In accessibility contexts, serious games are increasingly used for vision therapy, cognitive rehabilitation, motor skill development, and social skills training…

Shadow Speaking(also: Shadow Captioning, Respeaking)

A captioning technique where a trained human operator listens to live speech and repeats (or "respeaks") it clearly into a speech recognition system, which then generates real-time captions. The shadow speaker simplifies and normalizes the speech — removing overlapping dialogue,…

Shape Display(also: 2.5D Shape Display, Pin Display, Tactile Shape Display)

A physical computing device consisting of a grid of motorised pins that can be raised and lowered to create dynamic tactile relief surfaces. Shape displays render digital 3D content as physical topographies that users can explore by touch, providing real-time haptic feedback…

Shape-changing Interface(also: Shape-changing haptic interface, Morphing interface)

A physical interface that conveys information by changing its own shape or physical orientation — for example, a servo-driven lever that rotates to point in a specific direction, a cube whose top half turns to indicate a heading, or a surface that deforms under the user's hand.…

Shared Augmented Reality(also: S-AR, Co-Located AR, Collaborative AR)

An augmented reality setup in which multiple users share a spatially aligned view of virtual content anchored in the same physical environment. Each user wears a head-mounted display and can see and interact with the same virtual objects in real-time. In low-vision…

Shared Control(also: Collaborative Control, Shared Autonomy)

An assistive technology design approach in which control over a system is dynamically distributed between a user with a disability and an assistant (human or automated), allowing each party to manage the aspects best suited to their abilities. Unlike fully independent or fully…

Shared Movement(also: Linked Locomotion, Guided Movement)

A virtual reality interaction technique that allows one user to move through a virtual environment by attaching to or following another user's avatar, inspired by the physical sighted guide technique used by blind and low vision people. In shared movement, a user can grab a…

Shared control(also: Collaborative control, Blended control)

A control paradigm in assistive technology where input from multiple sources — such as a wheelchair user and a companion, or a user and an autonomous system — is combined to produce a single action. Shared control enables collaborative interaction that can adapt to the user's…

Shorelining(also: Trailing)

An orientation and mobility technique in which a person with a visual impairment follows a consistent surface edge — such as a wall, curb, edge of a sidewalk, or other contrasting surface — to maintain a specific orientation and navigate through an environment. The technique…

Sighted Assistance(also: Visual Interpreting, Remote Sighted Assistance)

Sighted assistance refers to services that connect blind or low-vision individuals with sighted people who can provide visual information on demand, typically through a live video call from a smartphone or smart glasses. Services like Be My Eyes (volunteer-based) and Aira…

Sighted Guide(also: Sighted Guide Technique, Human Guide)

A technique in which a sighted person assists a blind or low vision individual with navigation and orientation by serving as a visual reference and mobility aid. In physical settings, the blind person typically holds the guide's arm just above the elbow and walks a half-step…

Sign Language Dictionary(also: SL Dictionary, ASL Dictionary)

A reference tool that allows users to look up signs in a sign language, providing video demonstrations, definitions, and usage examples. Sign language dictionaries can be organized by English gloss (word-based lookup), linguistic features (handshape, location, movement), or…

Sign Language Interface(also: Sign-language interface, Signing interface)

A computing interface that accepts input from, or presents output to, a user in a signed language such as American Sign Language (ASL) or British Sign Language (BSL), rather than assuming a spoken or written language. Sign-language interfaces span sign-language recognition…

Sign Language Machine Translation(also: English-to-ASL Translation, Sign Language MT, Text-to-Sign Translation)

The automatic translation of written or spoken text into a signed language (or vice versa) using computational methods, typically producing output as an animated signing avatar or, less commonly, as recorded video clips. Because signed languages such as American Sign Language…

Sign Language Synthesis(also: Sign Language Generation, Sign Language Avatar, Signing Avatar)

Sign language synthesis is the automated generation of sign language output, typically through 3D animated avatars or computer graphics, from text or other input. The technology involves translating written or spoken language into the grammar, vocabulary, and spatial expressions…

Sign language(also: Manual language, Visual-gestural language)

A natural language that uses manual articulation (handshapes, movement, location relative to the body), facial expressions, and body posture to convey meaning, serving as the primary or preferred language of many deaf and hard-of-hearing people. Sign languages are fully…

Sign language animation(also: ASL animation, Signing avatar technology)

Computer-generated animated characters that produce sign language from text or script input, offering a potentially scalable alternative to pre-recorded human signer videos for making information accessible to deaf users. Sign language animation systems must convey not only…

Sign language avatar(also: Signing avatar, Virtual signer)

A computer-generated animated character that produces sign language from text or speech input. While sign language avatars hold potential for scaling deaf accessibility, their premature deployment raises significant concerns: the World Federation of the Deaf and World…

Sign language translation(also: SLT, Sign-to-text translation)

The automatic conversion of sign language video into written or spoken language text using machine learning. Unlike sign language recognition, which identifies individual signs or glosses, sign language translation produces fluent natural language output that accounts for the…

Signal Drift(also: Baseline Drift, DC Drift)

Signal drift is the gradual, unintended change in the baseline level of a measured signal over time, caused by factors unrelated to the intended measurement. In bio-electrical sensing for assistive technology, drift is a major challenge — for example, in electrooculography…

Signal Fingerprinting(also: Wireless Fingerprinting, RF Fingerprinting, Bluetooth Fingerprinting)

Signal fingerprinting is a technique used in indoor positioning systems where the unique pattern of wireless signal strengths (such as Bluetooth, Wi-Fi, or RFID) at specific locations within a building is recorded and stored as a reference map. During navigation, a mobile device…

Signal-to-Noise Ratio(also: SNR, S/N Ratio)

A measure of the strength of a desired signal relative to background noise, expressed in decibels (dB). In accessibility, signal-to-noise ratio is critical for the effectiveness of auditory interfaces: if background noise is too high relative to device audio output, speech…

Signature Guide(also: Writing Guide, Handwriting Guide)

A small rectangular card, typically credit-card sized, with a cutout opening that enables blind people to write or sign in a straight line on paper. Signature guides are one of the simplest and most widely used low-tech assistive tools for blind people, providing a tactile frame…

Signer-Independent Recognition(also: signer-independent SLR)

A sign language recognition approach designed to work with signers whose data was not included in the training set. Similar to speaker-independent speech recognition, signer-independent systems must handle variations in signing style, hand size, speed, and regional signing…

Signing Avatar(also: Sign Language Avatar, Virtual Signer)

A 3D computer-generated character that produces sign language through animated hand movements, facial expressions, and body posture. Signing avatars are used in educational contexts to deliver accessible sign language instruction, provide real-time multi-angle content, and offer…

Signing Avatar(also: Sign Language Avatar, Virtual Signer)

A computer-generated animated character that produces sign language output, translating text or spoken content into visual sign language for deaf and hard of hearing users. Signing avatars are used in applications such as public digital terminals, websites, and educational…

Silent Speech(also: Silent Speech Interface, SSI)

Communication technologies that generate intelligible speech from non-acoustic signals produced during the intent or attempt to speak, without requiring audible voicing. Input modalities include surface electromyography of articulatory muscles, ultrasound tongue imaging,…

Simplified Interface(also: Reduced Complexity Interface, Easy Mode)

A user interface design that intentionally reduces the number of features, options, and interaction steps to make a product or service accessible to users who would be overwhelmed by a standard interface. Simplified interfaces typically remove non-essential functionality,…

Single Switch(also: Single Switch Access, One Switch)

An assistive technology input device that provides a single binary action — on or off — enabling people with severe motor impairments to interact with computers and communication devices. Switches can be activated by virtually any reliable voluntary movement, including a blink,…

Single-Message AAC Device(also: BIGmack, Single-Switch Communicator, Voice Output Communication Aid)

A simple augmentative and alternative communication (AAC) device that records and plays back a single message when activated, typically via a large button or switch. Examples include the BIGmack Switch and similar products. These devices are often used as introductory AAC tools…

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…

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…

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…

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 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…

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…