Glossary

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Electromagnetic Tracking(also: Magnetic Tracking, 6-DOF Tracking)

Electromagnetic tracking is a position and orientation sensing technology that uses electromagnetic fields to determine the location and rotation of a sensor in three-dimensional space. Systems like the Polhemus tracker generate a low-frequency magnetic field from a stationary…

Electromyography(also: EMG, Electromyogram)

Electromyography (EMG) is a technique for measuring the electrical activity produced by muscles when they contract or are at rest. In accessibility and assistive technology, EMG sensors placed on the skin can detect muscle activations even when there is no visible movement,…

Electronic Assistive Technology(also: EAT, Electronic AT)

Computer-based devices and systems that enable people with severe disabilities to perform tasks they would otherwise be unable to accomplish, including communication, environmental control, mobility, and computer access. Electronic assistive technologies are often integrated…

Electronic Travel Aid(also: ETA)

An electronic device designed to help blind or visually impaired people navigate their environment by detecting obstacles and conveying spatial information through non-visual feedback such as audio cues, vibrations, or tactile signals. Electronic travel aids range from simple…

Electrooculogram(also: EOG, Electrooculography)

The electrooculogram (EOG) is a technique for measuring the electrical potential difference between the front and back of the eye using surface electrodes placed around the eyes. This corneal-retinal potential (CRP) varies linearly with eye rotation along both horizontal and…

Electropalatography(also: EPG, Dynamic Palatography, Palatography)

A technique for recording tongue-palate contact during speech using an artificial palate fitted with electrodes. When the tongue touches the palate, it completes a low-amperage electrical circuit that is detected and displayed visually in real time. In accessibility and deaf…

Electrotactile Feedback(also: Electrotactile, Electrical Tactile Stimulation)

A form of haptic feedback that uses controlled electrical current applied directly to the skin or through a thin insulating layer to generate tactile sensations. Unlike vibrotactile feedback (which uses mechanical vibration) or pressure feedback (which uses physical force),…

Emacspeak(also: The Emacspeak Audio Desktop)

A free, open-source speech output system built on top of the Emacs text editor that provides complete auditory access to a computing environment for blind and visually impaired users. Created by T. V. Raman in 1994 and still actively maintained, Emacspeak pioneered the concept…

Embodied Conversational Agent(also: ECA, Virtual Agent, Animated Agent)

A computer-generated animated character designed to interact with human users using multiple simultaneous communication channels — typically speech, eye gaze, facial expression, head and body posture, and hand gestures. ECAs are used in tutoring systems, customer-service agents,…

Embossed Braille(also: Hard Copy Braille, Paper Braille)

Braille text produced by physically raising dots on paper or other materials, creating a tactile surface that can be read by touch. Embossed Braille is produced using Braille embossers (printers), slates and styluses, or Braille typewriters such as the Perkins Brailler. It…

Embossed Graphics(also: Embossed Tactile Graphics, Raised Graphics)

Tactile graphics produced by a braille embosser or similar device that creates raised dots and lines on heavy paper or card stock. Embossed graphics are one of the most common methods for producing tactile representations of visual information for blind and visually impaired…

Embossed Paper(also: Raised Paper, Tactile Paper)

Paper that has been processed to create raised textures, shapes, or text that can be perceived through touch. In accessibility contexts, embossed paper is used to represent visual information non-visually, including diagrams, user interface layouts, maps, and graphical elements.…

Embosser(also: Braille Embosser, Tactile Graphics Embosser)

A device that creates raised (embossed) output on paper or other materials, used to produce braille text and tactile graphics for people who are blind or have low vision. Braille embossers function similarly to printers but press dots upward into heavy paper to create tactile…

Embossing(also: Braille Embossing, Tactile Embossing)

The process of creating raised patterns on paper or other materials by pressing from behind, producing content that can be read by touch. In accessibility, embossing is the primary method for producing Braille text and tactile graphics. Braille embossers are specialized printers…

Emergent Communicator(also: Beginning Communicator, Pre-Symbolic Communicator)

A person who is in the early stages of learning to use symbolic communication — understanding that symbols, words, pictures, or signs can represent objects, actions, and concepts. Emergent communicators may use a combination of gestures, vocalizations, facial expressions, and…

Emotional Agency

The ability of an individual to independently manage their emotional responses and experiences, particularly when encountering sensitive or personal information. In the context of accessibility and generative AI, emotional agency refers to the capacity of blind and low vision…

Emotional Design

A framework developed by Don Norman describing how people evaluate and form attachments to products through three cognitive levels: visceral (immediate sensory and aesthetic responses), behavioral (functional performance and usability), and reflective (personal meaning,…

Empathy Lab(also: Accessibility Lab, Assistive Technology Lab, AT Lab)

A dedicated physical or virtual space where designers, developers, and other team members can experience digital products using assistive technologies and simulations of various disabilities. Empathy labs typically include screen readers, switch devices, eye-tracking systems,…

End Effector(also: Haptic Stylus, Haptic Pen)

The physical component of a haptic device that the user directly touches or manipulates to interact with a virtual environment. In assistive technology contexts, end effectors translate digital information into tactile sensations — the device applies forces, vibrations, or…

End-User Programming(also: EUP, End-User Development, EUD)

A design approach that enables people without formal programming training to create, modify, or combine software behaviors to suit their own needs. Typical end-user programming systems expose computational building blocks through accessible interfaces such as visual block…

Energy Conservation(also: Energy management)

Energy conservation refers to a set of self-management strategies designed to help people with chronic conditions, fatigue-related disabilities, or fluctuating energy levels maintain function and independence by using their available energy efficiently. Core techniques include…

Engagement Detection(also: Engagement Monitoring, Engagement Recognition)

The use of sensors, computer vision, or other technologies to automatically assess whether a person is actively engaged with a task, device, or activity. Engagement detection systems typically monitor observable behaviours such as gaze direction, touch interaction patterns,…

Enhanced Activities of Daily Living(also: EADLs, EADL (gerontology), Advanced Activities of Daily Living)

In gerontology and human-robot interaction research, the highest tier of everyday activities — higher-order social, recreational, and civic pursuits that enable full participation in society, such as using computers and the internet, volunteering, engaging in hobbies, pursuing…

Enhanced Area Touch(also: Area Touch, Expanded Touch Area)

A touchscreen interaction technique that enlarges the effective touch point from a single pixel to a larger circular area, expanding both the motor space (the physical area the user needs to target) and the visual space (the on-screen representation of targets). When multiple…

Environmental Awareness(also: Situational Awareness, Environmental Sound Awareness)

The perception and understanding of what is happening in one's physical surroundings, particularly through auditory cues. For Deaf and hard of hearing individuals, environmental awareness is often reduced because many everyday signals — appliance timers, doorbells, approaching…

Environmental Control(also: Environmental Control Unit, ECU, Smart Home Control)

Technology that enables people with severe physical disabilities to independently control aspects of their environment such as lights, doors, temperature, televisions, phones, and other electronic devices. Environmental control systems can be operated through various access…

Environmental Control System(also: ECS, Electronic Aids to Daily Living, EADL)

An environmental control system (ECS) is an assistive technology that enables people with physical disabilities to independently control devices and features in their environment, such as lights, doors, televisions, phones, and computers. ECS devices accept input through various…

Envision AI(also: Envision)

An AI-powered visual assistance technology available as a smartphone app and as smart glasses that provides scene descriptions, text reading, and object identification for blind and low vision users. Envision uses computer vision and large language models to describe visual…

Equalization(also: EQ, Audio Equalization, Adaptive Equalization)

The process of adjusting the balance of frequency components in an audio signal by boosting or attenuating specific frequency bands. In accessibility contexts, adaptive equalization can be used to compensate for background noise by selectively boosting frequencies that are being…

Ergonomic Keyboard(also: Ergonomic Input Device)

A keyboard designed to reduce physical stress, strain, and injury risk during typing by conforming to the natural posture and biomechanics of the hands, wrists, and arms. Ergonomic keyboard designs include split keyboards (angled halves to reduce ulnar deviation), tented…

Event-Related Potential(also: ERP)

An event-related potential (ERP) is a measured brain response that is the direct result of a specific sensory, cognitive, or motor event. ERPs are extracted from electroencephalography (EEG) recordings by averaging brain signals time-locked to repeated presentations of a…

Exergame(also: Exercise game, Active video game, Fitness game)

A video game that requires physical movement or exercise as the primary interaction mechanism, combining gameplay elements like scoring, levels, and achievements with physical activity. Accessible exergames for people with disabilities use alternative feedback modalities — such…

Exergame(also: Exercise Game, Active Video Game, Exergaming)

A video game that requires physical movement or exercise as the primary input mechanism, combining gameplay with physical activity. Exergames have been developed for consoles, virtual reality systems, and mobile devices, with applications in rehabilitation, fitness, and physical…

Exergaming(also: Exercise Gaming, Active Gaming, Exergames)

A category of digital games that require physical movement or exercise as the primary means of interaction, combining gameplay with physical activity. Exergames use motion sensors, pressure pads, cameras, cycling devices, or other physical interfaces to translate body movements…

Exoskeleton(also: Robotic Exoskeleton, Wearable Exoskeleton)

A wearable mechanical or robotic device that fits around a part of the body — typically the hand, arm, or leg — and provides powered movement assistance, resistance, or guided motion. In rehabilitation contexts, exoskeletons are used to support intensive, repetitive motor…

Explainable AI(also: XAI, Interpretable AI)

A set of methods and design approaches that make the outputs and decision-making processes of artificial intelligence systems understandable to human users. Explainable AI aims to provide transparency about why an AI produced a particular result, typically through confidence…

Explore by Touch(also: Touch Exploration)

A screen reader interaction mode on touchscreen devices in which users drag their finger across the screen to discover and hear descriptions of interface elements beneath their fingertip. When Explore by Touch is active, a single tap does not activate a control — instead, the…

Extended Reality(also: XR, Cross Reality)

An umbrella term encompassing all immersive technologies that blend physical and virtual environments, including virtual reality (VR), augmented reality (AR), and mixed reality (MR). In accessibility, extended reality technologies offer promising assistive applications — smart…

External Memory

Information held outside the brain — in notes, calendars, photographs, voice recordings, alarms, labelled objects, or digital systems — that a person draws on to remember names, dates, tasks, procedures, or autobiographical content. External memory is a core accessibility…

External Metadata(also: Accessibility Metadata Overlay, Third-Party Metadata)

External metadata in the context of web accessibility refers to supplementary information stored separately from a web page that can be applied to improve the page's accessibility without modifying the original source code. This approach allows volunteers, developers, or…

Extractive Summarization(also: Extractive Text Summarization)

Extractive summarization is a natural language processing technique that creates summaries by selecting and preserving key words, phrases, or sentences directly from the original text, rather than generating new text (which is called abstractive summarization). In accessibility…

Eye Cursor(also: Gaze Cursor)

A visual indicator displayed on screen that shows where an eye tracking system has determined the user is currently looking. The eye cursor serves the same function as a mouse cursor but is controlled by eye gaze rather than hand movement. Because eye gaze is inherently less…

Eye Gaze Technology(also: Eye Control Technology, Gaze Control)

Technology that tracks and responds to eye movements, enabling users to control electronic devices using only their eyes. Eye gaze technology typically uses infrared cameras to track pupil position and gaze direction, allowing users to move cursors, make selections, type text,…

Eye Tracking(also: Gaze Tracking)

Technology that detects and follows the movement of a user's eyes, enabling gaze-based interaction, attention monitoring, and foveated rendering. In accessibility contexts, eye tracking serves as an alternative input method for users who cannot use traditional controllers,…

Eye Tracking(also: Gaze Tracking, Eye-Tracking)

A research methodology and assistive technology that measures where a person looks (fixation points), how their gaze moves across a display (saccades), and how long they focus on specific areas (dwell time). In accessibility research, eye tracking reveals how users visually…

Eye tracking(also: Gaze tracking, Eye-gaze tracking, Eye Tracker)

A technology that measures where a person is looking on a screen or in an environment by detecting eye position and movement, typically using infrared light and cameras. In accessibility, eye tracking serves dual roles: as an assistive input method allowing people with severe…

Eye-Gaze Control(also: Gaze Control, Eye-Controlled Interface, Gaze-Based Input)

An input method that uses eye-tracking technology to detect where a user is looking and translates gaze direction into control commands for computers, wheelchairs, communication devices, and other systems. Eye-gaze control is essential for people with severe motor disabilities —…

EyeDraw(also: Eye Draw)

A software application developed at the University of Oregon that enables people with severe motor impairments, particularly children, to create freehand drawings using eye movements tracked by an eye tracker. EyeDraw uses a two-state interaction model where users alternate…

EyeMusic

A visual-to-auditory sensory substitution device that converts images into sound, enabling people who are blind to perceive visual information including shape, location, and color. EyeMusic uses a left-to-right sweep algorithm where horizontal position maps to time, vertical…

Eyelid Gesture(also: Eyelid Interaction, Eyelid-Based Input)

An eyelid gesture is a deliberate eye movement used as an input method for controlling digital devices, involving intentional opening and closing of one or both eyelids in specific patterns, sequences, and durations. Unlike simple blink detection, eyelid gestures exploit the…