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Glossary

Terms used in accessibility research and practice. Each entry has a definition, common aliases, and category tags.

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Gaze Input(also: Eye Tracking Input, Gaze-Based Interaction, Eye Control)
An input method that uses eye-tracking technology to detect where a user is looking, enabling interaction with digital interfaces through eye movements such as fixation (dwelling on a target), smooth pursuit (following a moving target), or blinks. Gaze input is a critical…
Gaze Interaction(also: Gaze-Based Interaction, Gaze Input, Eye Gaze Control)
Gaze interaction is a method of controlling computers and devices by tracking where a person is looking on the screen. Using eye-tracking technology, the system detects the user's point of gaze and translates it into cursor movement or selection actions, often combined with…
Gaze Tracking(also: Eye Tracking, Eye Gaze Tracking)
Technology that measures and records eye movements to determine where a person is looking, for how long, and in what pattern. In low-vision research and rehabilitation, gaze tracking can reveal visual strategies such as fixation patterns, saccade paths, and preferred retinal…
Gaze Typing(also: Eye Typing, Gaze-Based Text Entry, Eye-Typing)
A text input method that uses eye tracking technology to allow users to type by looking at keys on a virtual on-screen keyboard. The most common technique is dwell-based selection, where the user fixates on a letter for a set duration (typically 300-1000 milliseconds) to select…
Gaze-Based Communication(also: Eye Gaze Communication, Gaze-Based AAC)
A form of augmentative and alternative communication that uses eye movement tracking to enable people with severe motor and speech impairments to select words, phrases, symbols, or commands on a screen. Users make selections by fixating their gaze on a target for a set dwell…
Gaze-Based Interaction(also: Gaze Input, Eye-Gaze Interaction, Gaze Control)
An interaction method where users control digital interfaces by directing their visual gaze at on-screen targets, typically detected through eye tracking or head orientation tracking. In accessibility contexts, gaze-based interaction provides an alternative input modality for…
Gazepoint(also: Gaze Point, Point of Gaze)
The specific point on a screen or surface where a person is looking at any given moment, as determined by an eye tracking system. The gazepoint is calculated from the gaze vector — the line extending from the eye to the display — and is typically reported as x,y coordinates. Eye…
Geographic Information System(also: GIS)
A system for capturing, storing, analyzing, and displaying geographically referenced spatial data. In accessibility, GIS technology underpins navigation and wayfinding tools for blind and visually impaired users by providing detailed environmental databases that can be queried…
Gerontechnology(also: Gerontech)
An interdisciplinary field combining gerontology (the study of aging) and technology to design products, services, and environments that support the health, independence, and quality of life of older adults. Gerontechnology addresses the specific needs and abilities of aging…
Gestural Interface(also: Gesture-Based Interface, Gestural Controller)
An input device or system that interprets body movements, hand gestures, or physical expressions as control signals for digital systems. In accessibility and music contexts, gestural interfaces are particularly relevant for d/Deaf and Hard of Hearing users who communicate…
Gesture Input(also: Gestural Input, Gesture-Based Input)
A form of human-computer interaction where users perform physical movements—such as swipes, taps, pinches, or mid-air hand motions—to issue commands or provide input to a digital device. Gesture input is fundamental to touchscreen smartphones, tablets, and increasingly to…
Gesture Recognition(also: Gesture Detection)
The computational process of identifying and interpreting human gestures—typically hand, arm, or body movements—using sensors and machine learning algorithms. Gesture recognition systems analyze data from cameras, accelerometers, gyroscopes, or other sensors to classify…
Gesture-based interaction(also: Gestural interface, Touchless interaction)
An interaction modality where users control technology through body movements, hand gestures, or postures detected by sensors such as depth cameras, rather than through traditional input devices like keyboards, mice, or touchscreens. Gesture-based interaction can benefit people…
Global Public Inclusive Infrastructure(also: GPII)
A framework and set of technologies designed to allow people with disabilities to automatically have their accessibility preferences and settings applied across any device, platform, or service they encounter. GPII enables portable user profiles that specify needs such as large…
GoodMaps
GoodMaps is an accessible indoor navigation platform that provides detailed indoor maps and turn-by-turn navigation for blind and low-vision users in buildings such as airports, transit stations, hospitals, and government offices. The system uses a combination of smartphone…
Grab Bar(also: Safety Rail, Support Bar, Handrail)
A rigid, wall-mounted bar designed to provide support and stability for people who need assistance maintaining balance, transferring between positions, or preventing falls. Grab bars are most commonly installed near toilets, bathtubs, and showers, but may also be placed in…
Graphic Input Device(also: Drawing Input Device, Graphic Tablet)
A hardware device used to input and manipulate visual graphics on a computer, including digital drawing pads (digitizer tablets), styluses, mice, trackballs, touchscreens, and specialized assistive devices. For artists with upper limb motor impairments, the shape, size, pressure…
Graphic Transcription(also: Image Transcription, Accessible Graphic Transcription)
The process of converting visual graphics (charts, maps, floor plans, diagrams) into formats accessible to blind and visually impaired users, such as tactile graphics, audio descriptions, or interactive multimodal representations using sonification and speech. Graphic…
Graphical Semantic Enhancement(also: Semantic Graphics, Labeled Graphics)
The practice of enriching graphical objects with meaningful text labels, descriptions, and metadata so that they can be understood non-visually. In accessible drawing and diagramming tools, graphical semantic enhancement allows users to assign descriptive labels to shapes,…
Graphical User Interface(also: GUI)
A type of computer interface that uses visual elements such as windows, icons, menus, and pointers to allow users to interact with software, as opposed to text-based command-line interfaces. GUIs present significant accessibility challenges for blind and low-vision users because…
Graphics Tablet(also: Drawing Tablet, Pen Tablet, Digitiser Tablet)
An input device consisting of a flat surface on which a user draws or points with a stylus to interact with a computer. Graphics tablets translate the position and pressure of the stylus into cursor movements on screen. For users with motor impairments who find a mouse difficult…
Graspable Interface(also: Graspable User Interface)
A graspable interface is a type of tangible user interface in which users interact with a computer system by physically grasping and manipulating real-world objects that are tracked by the system, typically through camera-based image processing or embedded sensors. Unlike…
Gravity Well(also: Target Attraction, Sticky Targets, Snap-to-Target)
An interaction filtering technique that warps the cursor space around interactive targets (such as buttons or links), creating attractive basins that pull the cursor toward the nearest target. This makes it easier for users with motor impairments to select small or distant…
Grid Display(also: Symbol Grid, Grid-Based AAC)
A common AAC layout format that presents communication options as symbols, icons, or words arranged in a grid pattern of rows and columns. Grid displays are widely used in speech-generating devices and AAC apps, allowing users to construct messages by selecting individual…
Grid Recursion(also: Recursive Grid Navigation, Hierarchical Grid)
A navigation technique where a grid cell can be further subdivided into a finer sub-grid, allowing users to achieve progressively more precise positioning through successive levels of refinement. For example, a 3x3 top-level grid provides 9 positions; descending one level into a…
Grid-Based Interface(also: Grid Navigation Interface)
An interaction paradigm that divides a screen or workspace into a grid of cells, allowing users to navigate by specifying grid coordinates rather than precise pixel positions. Grid-based interfaces are particularly valuable for non-visual access because they provide a structured…
Grid-Based Navigation(also: Grid Navigation, Grid Cursor Control)
A speech-controlled cursor positioning technique that divides the screen into numbered regions, allowing users to select progressively smaller areas by speaking numbers until the cursor reaches the target location. This alternative input method enables people with upper-body…
Gross Motor Movement(also: Gross Motor Skills, Gross Motor Control)
Large body movements involving the major muscle groups of the arms, legs, and torso, as opposed to fine motor movements that require precise control of small muscles in the fingers and hands. In assistive technology, the distinction between gross and fine motor abilities is…
Guide Dog(also: Seeing Eye Dog, Service Dog, Dog Guide)
A specially trained assistance animal that helps blind or visually impaired individuals navigate their environment safely. Guide dogs are trained to avoid obstacles, stop at curbs and steps, and navigate around barriers, enabling their handlers to travel more independently. As a…
Guide Runner(also: Sighted Guide Runner, Running Guide)
A sighted person who accompanies a blind or visually impaired runner during training or competition, providing verbal navigation cues and physical guidance typically through a tether connecting the two runners. Guide runners must match the ability level of the BVI runner,…
HAAT Model(also: Human Activity Assistive Technology Model)
A conceptual framework for understanding and designing assistive technology systems that identifies four interconnected components: the human user, the activity being performed, the assistive technology itself, and the context in which the activity takes place. Developed by Cook…
HULOP(also: Human-scale Localization Platform)
An open-source indoor navigation platform originally developed by IBM Research to support blind navigation using Bluetooth Low Energy (BLE) beacon fingerprinting for localisation plus a topological map server for route planning and point-of-interest data. HULOP has been used as…
Hand Tracking(also: Gesture Tracking, Hand Gesture Recognition)
A technology that detects and tracks the position, orientation, and movements of a user's hands and fingers without requiring physical controllers, typically using cameras and computer vision algorithms. In extended reality, hand tracking enables hands-free interaction through…
Hand-Object Interaction(also: Hand-Object Interactions, HOI)
The full range of physical actions people perform when grasping, touching, holding, manipulating, or gesturing toward objects with their hands. In accessibility research, hand-object interactions are studied as natural intent cues that can drive assistive technology: for blind…
Hands-Free Control(also: Hands-Free Interaction, Hands-Free Input)
Any method of operating a device or computer system that does not require the use of the hands or fingers. Hands-free control encompasses a range of input techniques including voice commands, eye tracking, head movements, sip-and-puff switches, foot controls, and EMG-based…
Hands-Free Interface(also: Hands-Free Computing, Hands-Free Input)
A hands-free interface is a computer interaction system that does not require the use of hands or fingers, enabling users to control software through alternative input channels such as head movements, eye gaze, voice commands, foot pedals, or breath-controlled switches. These…
Hapget(also: Haptically-Enhanced Widget)
A hapget (haptically-enhanced widget) is a user interface element that combines a 3D visual representation with haptic (touch) feedback, audio cues, and descriptive metadata to enable non-visual interaction. Introduced in the 3D HapticWebBrowser project, hapgets transform…
Haptic(also: Haptic feedback, Haptic interface)
Relating to the sense of touch as a means of interaction between a user and a device. Haptic interfaces include braille displays that raise and lower pins to represent text, vibration motors in mobile devices that provide tactile feedback, and specialised controllers that offer…
Haptic Communication(also: Social Haptics, Tactile Communication, Haptic Interaction)
A method of conveying information through touch-based signals, vibrations, or physical patterns on the body. Haptic communication is particularly important for individuals with deafblindness or other multisensory impairments, where visual and auditory channels are unavailable or…
Haptic Controller(also: Haptic Interface, Tactile Controller)
An input device that uses touch-based interaction, typically through buttons, pads, or surfaces that can be pressed, tapped, or manipulated. In music technology, haptic controllers include devices like sample pads, drum machines, and synthesizer controllers that respond to…
Haptic Design(also: Vibrotactile Design, Haptic Authoring)
The practice of authoring haptic feedback - typically vibrations, forces, or temperature cues - so that it conveys intended meaning, emotion, or synchronicity with other media. Haptic design involves choosing signal parameters such as amplitude, frequency, timing, and spatial…
Haptic Device(also: Haptic Interface, Force-Feedback Device, Tactile Device)
A hardware device that provides tactile or force feedback to users, enabling them to feel virtual objects, textures, resistance, or vibrations. Haptic devices range from simple vibration motors in smartphones to sophisticated force-feedback systems like the Geomagic Touch…
Haptic Display(also: Tactile Display, Pin-Matrix Display, Refreshable Tactile Display)
A device that conveys information through the sense of touch by dynamically raising and lowering physical elements (typically pins) to create tactile patterns. In accessibility, haptic displays range from single-line refreshable Braille displays used with screen readers to large…
Haptic Exploration(also: Tactile Exploration, Touch Exploration)
The process of acquiring spatial and object information through systematic touch and hand movements. Haptic exploration involves active manipulation and movement across surfaces to perceive shape, size, texture, temperature, and spatial relationships. For people who are blind or…
Haptic Feedback(also: Tactile Feedback, Touch Feedback)
Information conveyed through the sense of touch, typically using vibrations, force, or texture changes to communicate data or system states to a user. In accessibility, haptic feedback provides non-visual, non-auditory confirmation of actions and can convey spatial information,…
Haptic Feedback(also: Tactile Feedback, Haptics)
Technology that communicates information through the sense of touch, using vibrations, pressure, or motion applied to the user's body. In accessibility, haptic feedback provides a non-visual, non-auditory channel for conveying alerts, navigation cues, or interface responses —…
Haptic Glove(also: Data Glove, Tactile Glove, Wearable Haptic Device)
A wearable device worn on the hand that provides tactile feedback through vibration motors, piezoelectric actuators, pin arrays, or other mechanisms embedded in the fingers and palm. In accessibility research, haptic gloves have been explored for several applications: enabling…
Haptic Graphics(also: Dynamic Tactile Graphics, Refreshable Haptic Graphics)
Graphical information presented through the sense of touch, typically on refreshable displays or touchscreen devices. Unlike static tactile graphics (embossed paper or thermoform), haptic graphics can change dynamically and often combine tactile feedback with audio cues. Modern…
Haptic Guiding(also: Force-Based Guiding, Haptic Navigation)
A collaborative interaction technique where one user physically guides another user's cursor or pointer through force feedback, allowing spatial information to be communicated through touch rather than verbal description. In inclusive group work, haptic guiding enables sighted…
Haptic Handle(also: Tactile handle)
A grip on a mobility or guidance device (robot, smart cane, haptic rein, etc.) that conveys information to the user through touch — typically via buttons, vibrotactile feedback, or physical coupling to the device's motion. On suitcase-shaped navigation robots for blind users, a…