Glossary

Searchable terminology from accessibility, web standards, and related fields.

840 results found in assistive technology.

On-Body Gesture (On-Body Interaction, Body-Based Gesture)
A gesture performed on or against one's own body rather than on a device surface or in the air. Examples include tapping the thigh, swiping along the forearm, or touching the ear to trigger a command …
On-Screen Keyboard (Virtual Keyboard, Software Keyboard, OSK)
A software application that displays a visual representation of a keyboard on the computer screen, allowing users to type by selecting keys with a pointing device, head tracker, eye gaze system, or sw…
One-Handed Input (Single-Handed Operation, One-Handed Operation)
One-handed input refers to interaction techniques and interface designs that can be operated using a single hand, accommodating users who have limited use of one limb due to amputation, hemiplegia, st…
Open-Source Hardware (OSHW)
Physical devices and components whose design specifications are publicly available for anyone to study, modify, distribute, and manufacture. In the assistive technology space, open-source hardware ena…
OpenDyslexic (Open Dyslexic)
A free, open-source typeface specifically designed to improve readability for people with dyslexia. The font uses heavier bottom portions on letters to help prevent visual rotation and uses unique let…
Optacon (Optical-to-Tactile Converter)
A historical assistive device developed in the 1970s that enabled blind people to read printed text by converting visual images of letters into tactile vibration patterns felt with the fingertip. User…
Optical Character Recognition (OCR, Text Recognition)
Technology that converts images of text—whether typed, handwritten, or printed—into machine-readable text data. OCR is used in accessibility to extract text from images, documents, video frames, and r…
Optical Character Recognition (OCR) (OCR, Text Recognition)
Technology that converts images of text — such as scanned documents, photographs of signs, or PDF pages stored as images — into machine-readable text that can be processed by screen readers, search en…
Opticon (Optical-to-Tactile Converter)
An early assistive technology device developed by Dr. James Bliss in the 1960s that converts printed text into a tactile vibrating pattern that can be read with the fingertip. The Opticon uses a small…
Option Repertoire
A type of technology repertoire where a person has multiple tools that can each independently address the same access barrier, choosing between them based on context. For example, a person might use f…
PDF Remediation (PDF Tagging, PDF Accessibility Remediation, Document Remediation)
The process of adding structural tags to an existing PDF document to make it accessible to assistive technologies such as screen readers. Remediation involves identifying logical content elements (hea…
PHANTOM (PHANTOM Omni, PHANTOM Desktop, SensAble PHANTOM)
A family of force-feedback haptic devices originally developed by SensAble Technologies (now part of 3D Systems). PHANTOM devices use a pen-like stylus that users grasp while motors apply forces to cr…
Page Turner (Page Turning Aid)
Any device, tool, or person that assists a musician in turning the pages of a music score during performance. Traditional page turners are human assistants who sit beside a musician and turn pages on …
Paradox of the Active User
The Paradox of the Active User, identified by Carroll and Rosson (1987), refers to the observation that computer users systematically avoid investing time in learning more efficient tools or methods, …
Parametric design (Parametric modeling)
A design approach in which objects are defined by adjustable parameters (dimensions, angles, ratios) rather than direct geometric manipulation, allowing users to customize designs by changing numerica…
Passive Sensing (Passive Monitoring, Ambient Sensing)
The collection of behavioral and physiological data through sensors without requiring active user input. In mental health contexts, passive sensing uses smartphone sensors (GPS, accelerometer, microph…
Passive notification (Automatic notification, Push notification)
Information delivered to a user automatically without requiring active input, triggered by context such as location, time, or system state. In assistive navigation for people with visual impairments, …
Pedestrian Dead Reckoning (PDR, Inertial Navigation)
A localization technique that estimates a pedestrian's position by tracking their movement from a known starting point using inertial sensors (accelerometers and gyroscopes) found in smartphones. The …
Peltier Module (Peltier Device, Thermoelectric Module, TEC Module)
A Peltier module is a thermoelectric device that creates a temperature difference when electrical current is applied, with one side heating up and the other cooling down. In assistive technology, flex…
Perceptual Computing (Perceptual Intelligence)
A computing paradigm in which systems use sensors such as cameras, microphones, and motion detectors to perceive and interpret human behaviour, including gestures, facial expressions, speech, and body…