Glossary

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Imaginary Interface(also: Spatial Memory Interface, Empty-Handed Interaction)

An interaction paradigm where users interact with a virtual interface mapped to empty space or their own body, without any physical device in the interaction area. Users transfer their spatial memory of familiar device layouts (like a smartphone screen) to their palm or mid-air,…

In-situ Highlighting(also: In-situ Guidance, In-situ Instruction, On-screen Highlighting)

In-situ highlighting is a tutorial technique that overlays visual indicators directly on the live application interface to show the user exactly where to tap, look, or interact next - rather than describing the action in a separate text or video tutorial. Common implementations…

Indoor Localization(also: Indoor Positioning, Indoor Positioning System, IPS)

The problem of determining the precise location of a person or device inside a building, where GPS signals are weak or unavailable. Indoor localization is foundational for accessible wayfinding systems aimed at blind and low-vision travellers, who need to know their position…

Inter-Icon Spacing(also: Icon Spacing, Icon Gap)

The amount of empty space between icons or interactive targets in a graphical user interface. Inter-icon spacing affects a user's ability to visually distinguish, locate, and accurately select individual icons, particularly for people with visual impairments or motor…

Interface Consistency(also: Consistent Navigation, Consistent Identification, UI Consistency)

Interface consistency is a design principle requiring that navigational mechanisms, visual layouts, and interactive components appear and behave in the same way across different pages, screens, or applications. In accessibility, consistency is critical because users who rely on…

Live Captions(also: Google Live Caption, Automatic Captions)

An Android accessibility feature that automatically generates real-time captions for any audio playing on the device, including videos, podcasts, phone calls, and video meetings. Unlike Live Transcribe which captures ambient speech, Live Captions processes audio output from the…

Live Transcribe(also: Google Live Transcribe)

An Android accessibility feature developed by Google that provides real-time speech-to-text transcription, displaying spoken words as text on the smartphone screen. Live Transcribe supports over 80 languages and is designed primarily for deaf and hard of hearing users to follow…

Location-Based Game(also: LBG, Location-Based Puzzle Game, LBPG)

A location-based game (LBG) is a game whose gameplay depends on the player’s real-world physical location, typically determined via GPS, NFC, Bluetooth beacons, or QR codes. Examples include Geocaching, Ingress, Pokémon GO, and a range of urban puzzle, treasure-hunt, and tourism…

Lookout(also: Google Lookout)

An Android accessibility application developed by Google that uses the smartphone camera and machine learning to identify objects, read text, scan documents, and describe surroundings for blind and partially sighted users. Lookout can identify currency, read food labels,…

M-Pesa(also: Mobile Money)

A mobile money transfer and financial services platform widely used in Kenya and other parts of Sub-Saharan Africa, allowing users to deposit, withdraw, transfer money, and pay for goods and services via their mobile phones. M-Pesa is deeply embedded in daily life in Kenya and…

Microinteraction(also: Micro-interaction, Quick interaction)

A brief, high-frequency interaction with a device that typically takes a sighted user less than four seconds to complete, such as checking the time, glancing at a notification, or adjusting the volume. Microinteractions are significant for accessibility because they expose…

Mobile AR(also: Smartphone AR, Handheld AR)

Augmented reality experiences delivered on commodity smartphones and tablets using the built-in camera, display, inertial sensors, and (increasingly) depth sensors, without specialized AR headsets. Mobile AR platforms such as Apple's ARKit and Google's ARCore provide plane…

Mobile Phone(also: Cell Phone, Cellular Phone, Mobile)

A mobile phone is a portable radio-telephone that connects to the public telephone network over cellular radio infrastructure. In digital-accessibility practice mobile phones are both an accessibility tool and an accessibility barrier: they are a primary delivery mechanism for…

Mobile Virtual Reality(also: Mobile VR, Smartphone VR)

Virtual reality systems delivered through a smartphone and consumer-grade accessories (wireless headphones, simple hand-held mounts) rather than a dedicated head-mounted display and PC rig. For accessibility, mobile VR is significant because it uses devices that blind and…

Mobile Web Best Practices(also: MWBP, MWBP 1.0)

A W3C recommendation published in 2006 that defines good usability and accessibility practices for delivering web content to mobile devices. Derived from the Web Content Accessibility Guidelines 1.0 (WCAG 1.0), Mobile Web Best Practices focuses on guidelines that have a direct…

Mobile Web Initiative(also: MWI, W3C Mobile Web Initiative)

The W3C Mobile Web Initiative (MWI) was a program launched in 2005 to improve the experience of accessing the web from mobile devices such as cell phones and handheld systems. Operating in a manner similar to the Web Accessibility Initiative (WAI), the MWI developed best…

MultiTap(also: Multi-Tap)

A standard text-entry method used on mobile phone keypads where groups of three or four letters are assigned to each numeric key, and users press the key consecutively to cycle through the available letters. For example, pressing the "2" key once produces "a," twice produces…

NavTap

A navigational text-entry method designed for blind mobile phone users that reduces the cognitive load associated with inputting text without visual feedback. NavTap organizes the alphabet into five rows beginning with vowels and allows users to navigate between letters using…

Near-Miss Detection(also: Near-Miss Interaction)

A strategy for identifying when a user almost but not quite succeeds at a device interaction, suggesting they might benefit from an accessibility accommodation. For example, if a user repeatedly attempts a double-click but falls just outside the required timing threshold, the…

Nomadic Text Entry(also: Mobile Text Entry, On-the-Go Texting)

The practice of inputting text on a mobile device while moving through or actively engaging with the physical environment, as opposed to typing while stationary. For people who are blind or visually impaired, nomadic text entry presents unique challenges because it requires…

Nonvisual Interaction(also: Eyes-Free Interaction, Screenless Interaction)

Interaction with computing devices without relying on visual feedback, using alternative channels such as audio, tactile, or proprioceptive cues. Nonvisual interaction is essential for blind and low-vision users but also benefits sighted users in eyes-busy contexts like driving…

Offline Access(also: Offline Mode, Disconnected Access, Offline-First)

The ability to use digital content, applications, or services without an active internet connection. Offline access is an important accessibility consideration because it ensures that users in areas with unreliable, expensive, or nonexistent connectivity — including many rural…

On-body Input(also: Skin-based Input, Body-based Interaction)

An interaction technique that uses the surface of the user's own body — typically the hand, arm, or other skin areas — as an input surface for controlling digital devices. On-body input is sensed through wearable cameras, depth sensors, capacitive touch sensors, or acoustic…

On-device Recognition(also: On-Device Inference, Edge Recognition)

Performing pattern recognition - such as sign language recognition, speech recognition, or computer vision - locally on the user's device rather than by sending input to a remote server. On-device recognition matters for accessibility because it preserves privacy (camera or…

Pedestrian Navigation(also: Pedestrian Wayfinding, On-Foot Navigation)

Pedestrian navigation refers to wayfinding and route-following on foot in outdoor environments, including sidewalks, crosswalks, public transit access points, and shared streets. For blind and low vision users, people with cognitive disabilities, and wheelchair users, the…

Pedestrian Navigation System(also: Pedestrian GPS, Walking Navigation)

A navigation system designed specifically for people travelling on foot, as opposed to systems designed for car drivers. Pedestrian navigation systems must account for footpaths, crosswalks, stairs, pedestrian bridges, and indoor routes that vehicle-focused systems typically…

QWERTY Keyboard(also: QWERTY)

A QWERTY keyboard is the dominant Latin-script keyboard layout, named for the first six letters on the top row, originally designed for mechanical typewriters and carried forward into computers and mobile devices. On mobile handsets, QWERTY has appeared in both hardware form…

Responsive Design(also: Responsive Web Design, RWD, Mobile First Design)

A web design approach in which layouts, images, and other content elements adapt fluidly to the size and capabilities of the user's device, providing an optimal viewing experience across desktops, tablets, and mobile phones without requiring separate versions of a site.…

Safety Check-in(also: Wellness Check-in, Check-in Call)

A safety check-in is a brief remote-communication exchange — most often a phone call, text, or app-based 'ping' — whose primary purpose is to confirm the safety and wellbeing of a person at a distance, rather than to exchange substantive information. The pattern is common in…

Screen Curtain(also: Display Curtain)

Screen Curtain is an accessibility feature available on iOS and some other platforms that turns off the device's display while keeping the device fully functional and responsive to touch input and screen reader output. Originally designed to save battery power for blind users…

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…

Smartphone Accessibility(also: Mobile Phone Accessibility)

The design and adaptation of smartphone hardware, operating systems, and applications to be usable by people with disabilities. Smartphones have become increasingly important as assistive technology platforms due to their widespread availability, built-in accessibility features…

Smartphones as Assistive Technology(also: Mobile AT, Phone-Based AT)

The use of mainstream smartphones as assistive devices through built-in accessibility features (screen readers, magnification, live captions, sound amplification) and downloadable applications that support independence for people with disabilities. In low- and middle-income…

Soft Key(also: Softkey, Context-sensitive Key)

A soft key is a physical button on a device whose labelled function changes depending on the current application or screen — typically indicated by an on-screen label positioned next to the button. Soft keys let hardware designers fit more commands into a limited number of…

Sound Amplifier(also: Google Sound Amplifier)

An Android accessibility feature that uses the smartphone's microphone and headphones to amplify and filter ambient sounds in real-time, making it easier for hard of hearing users to hear conversations and environmental audio. Sound Amplifier can boost quiet sounds, reduce…

Speech Input(also: Voice input, Voice control, Speech recognition input)

An input method that allows users to control devices or enter text by speaking rather than using manual touch or keyboard input. Speech input is particularly important for people with visual impairments, who use it significantly more often than sighted users to overcome the…

Speed Dial(also: One-touch Dialing, Quick Dial)

Speed dial is a mobile or landline phone feature that lets a user place a call to a preset contact by pressing one or two assigned digits rather than entering a full phone number. Originally introduced as a convenience feature, speed dial functions as a meaningful accessibility…

Spindex(also: Speech Index)

An auditory navigation technique that uses the first letter of each word (spoken or synthesized) as an index to speed up list navigation. When scrolling through alphabetically ordered lists like contacts, a spindex plays the first letter of each item, allowing users to quickly…

Split Tap(also: Split Tapping)

A touchscreen interaction technique where the user holds one finger on a target element while tapping with a second finger to activate it. Split tap allows blind users to explore the screen with one finger to locate elements (hearing each one announced) and then tap elsewhere to…

Steady Tapping

The ability to place a finger on a touchscreen target and hold it still long enough for the system to register a deliberate tap, as opposed to the unintentional movements caused by hand tremor. For users with motor impairments, maintaining a steady tap is a significant challenge…

Swift Playgrounds(also: Apple Swift Playgrounds)

A hybrid block-based and text-based programming environment developed by Apple for iPad and Mac that teaches coding using the Swift programming language. Swift Playgrounds is notable in the accessibility education space because it integrates with VoiceOver, includes tactile maps…

T9(also: Text on 9 Keys, Tegic T9)

T9 (Text on 9 Keys) is a dictionary-based predictive text-entry method developed by Tegic Communications in the 1990s for mobile phone keypads with multiple letters assigned to each numeric key. Rather than pressing a key multiple times to cycle through letters (the older…

Tactile Overlay(also: Touch Overlay, Tactile Screen Overlay)

A physical sheet or frame placed on top of a touchscreen or flat surface that provides raised tactile landmarks, borders, buttons, and contextual information for users who are blind or have low vision. Tactile overlays can be made from laser-cut cardboard, 3D printed materials,…

TalkBack(also: Android TalkBack, Google TalkBack)

The built-in screen reader for Android devices, developed by Google as part of the Android Accessibility Suite. TalkBack provides spoken feedback, vibration, and other audible cues to help blind and visually impaired users navigate their devices without seeing the screen. Users…

Tappability(also: Tap Target, Tappable)

The property of a user interface element that indicates whether it can be activated by tapping on a touchscreen device. Tappability is a key concern in mobile accessibility because elements that appear tappable but are not (or vice versa) create barriers for users who rely on…

Text Messaging(also: SMS, Short Message Service, Texting)

Text messaging is the exchange of short written messages between mobile devices over a cellular or data network, most commonly using the SMS (Short Message Service) or MMS (Multimedia Messaging Service) standards, or modern over-the-top messaging apps. Text messaging has been a…

Text Scaling Assistive Service(also: TSAS, Font Size Scaling)

An Android platform service that allows users to increase or decrease the size of text displayed across applications. Text Scaling Assistive Service is critical for users with low vision who need larger text to read content comfortably. Apps that fail to support TSAS properly…

Textonym(also: T9 Ambiguity)

Words that share the same sequence of key presses on a telephone-style number pad, such as "bat" and "cat" which both map to the key sequence 2-2-8. Textonyms are a significant design consideration in AAC and text entry systems that use reduced keyboard layouts, as the system…

Touch Accessibility(also: Touchscreen Accessibility)

The design and adaptation of touch-based interfaces to be usable by people with diverse motor, sensory, and cognitive abilities. Touch accessibility addresses challenges including insufficient target sizes for users with limited fine motor control, lack of alternatives to…

Touch Exploration(also: Explore by Touch, Touch-Based Exploration)

An interaction method that allows users to discover on-screen content by moving their finger across a touchscreen, receiving audio feedback about elements under the fingertip. Touch exploration is fundamental to how blind and low-vision users navigate mobile devices through…