Glossary

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Listening Window

The interval during which a voice assistant or speech-recognition system actively captures user audio after being activated (by wake word or button press). A short or fixed listening window causes premature cut-offs for users who pause while formulating speech — common for…

Literacy Bias(also: Literacy bias of a metric)

In accessibility research methodology, a literacy bias describes the phenomenon where an evaluation metric systematically produces different scores for participants with different reading-literacy levels, independent of the characteristic being measured. For example,…

Literacy Development(also: Literacy Learning, Reading Development)

The process of acquiring reading and writing skills, from early phonological awareness through fluent reading comprehension. Literacy development is a key focus of reading support technology research, particularly for children with disabilities. Technologies supporting literacy…

Literal language processing(also: Literal interpretation)

The tendency to interpret language at face value, understanding words and phrases according to their explicit, dictionary meaning rather than inferring implied, figurative, or contextual meanings. Literal language processing is common among many autistic individuals and can lead…

Live Captioning(also: Real-Time Captioning, Live Captions)

The process of converting spoken language into text displayed in real time, enabling Deaf and hard of hearing individuals to follow live audio content such as meetings, lectures, broadcasts, and events. Live captioning may be performed by human stenographers (CART providers),…

Live Captioning(also: Real-Time Captioning, CART)

The process of creating captions in real time as audio content is being produced, rather than from a pre-existing script. Live captioning is used in television news broadcasts, live events, videoconferences, and classrooms. It presents unique challenges including a natural…

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 Description(also: Real-Time Description, Live Audio Description)

The practice of providing descriptions of visual content in real time as events unfold, as opposed to scripted descriptions added during post-production of recorded media. Live description is used in contexts such as livestreaming, live theatre, sporting events, and…

Live Region(also: ARIA Live Region, aria-live)

A section of a web page that is dynamically updated and announced by assistive technologies without requiring the user to navigate to it. Live regions are defined using the WAI-ARIA aria-live attribute, which can be set to "polite" (announced when the screen reader is idle),…

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…

Lived Experience(also: First-Person Experience)

Knowledge and understanding gained through direct personal experience of a condition, situation, or identity, as distinct from theoretical or observational knowledge. In disability and accessibility research, lived experience is increasingly recognized as a valuable and…

Livestream Accessibility(also: Live Video Accessibility)

The practice of making live video broadcasts accessible to people with disabilities, particularly viewers with visual or hearing impairments. Livestreams present unique accessibility challenges because they feature multiple simultaneous visual elements (main video, webcams,…

Livestreaming(also: Live Streaming, Streaming)

Broadcasting real-time video content to an online audience, typically through platforms like Twitch, YouTube Live, or Facebook Gaming. Viewers can interact with streamers through text chat, creating a hybrid of performance and conversation. For accessibility, livestreaming…

LoRA(also: Low-Rank Adaptation)

A parameter-efficient fine-tuning technique, introduced by Hu et al. in 2022, in which a large pretrained neural network is specialised by training only a pair of small low-rank matrices that modify specific weight projections, while the original weights remain frozen. LoRA…

Local Navigation(also: Local guidance, Fine-grained navigation)

Navigation at the scale of a few metres, where the task is to bring a blind traveller into direct body-scale interaction with a specific landmark object — sitting in a particular chair, pressing an elevator button, reaching a door handle, boarding through a specific train door.…

Local-First Software(also: Local-First)

A software design philosophy, articulated by Kleppmann and colleagues in 2019, in which applications keep the user's primary data on local devices and treat cloud services as optional synchronization or backup layers rather than as the source of truth. Local-first systems aim to…

Localization(also: Position Estimation, Indoor Localization, User Localization)

Localization is the process of determining a user's position within an environment, typically using a combination of sensors such as GPS, inertial measurement units, BLE beacons, Wi-Fi signals, or computer vision. Accurate localization is the foundational challenge for all…

Location Awareness(also: Location-Aware Computing, Location Sensing)

The ability of a computing system to determine and respond to the physical location of a user or device, typically using GPS, Wi-Fi positioning, cellular triangulation, or other sensing technologies. In assistive technology, location awareness enables context-sensitive support…

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…

Location-Based Service(also: LBS, Location-Based Services)

A software application or platform that uses geographic position data — from GPS, Wi-Fi, Bluetooth beacons, or other localization technologies — to deliver context-aware information or functionality to users based on their physical location. In accessibility, location-based…

Locked-In Syndrome(also: LIS, Pseudocoma)

Locked-in syndrome is a rare neurological condition in which a person is fully conscious and cognitively aware but unable to move or speak due to complete paralysis of nearly all voluntary muscles, often resulting from a brainstem stroke or injury. People with locked-in syndrome…

Locomotion(also: VR Locomotion)

Methods by which users navigate and move through virtual environments in VR. Common locomotion techniques include free-roam (physical walking that maps to virtual movement), joystick-based continuous movement, teleportation (pointing to a destination and instantly moving there),…

Locomotion Technique(also: VR Locomotion, Virtual Travel Technique)

A locomotion technique is a method for navigating or moving through a virtual environment in virtual reality (VR). Because physical space is limited and many users are seated, locomotion techniques simulate travel without requiring real-world walking. Common approaches include…

LogMAR(also: Logarithm of the Minimum Angle of Resolution)

A standardised scale for measuring visual acuity based on the logarithm (base 10) of the minimum angle of resolution, used in the Bailey-Lovie eye chart and widely adopted in clinical vision research. A logMAR value of 0.0 corresponds to 20/20 (6/6) vision, with higher values…

Logical Control(also: Indirect Control)

An interaction paradigm where the user accesses specific functions supported by an application indirectly, typically by selecting from a presented set of options rather than performing the action directly. Examples include scanning through a menu of commands, using keyboard…

Logical Metaphor(also: Spatial Metaphor)

A design technique for haptic feedback where the physical location of a vibration on the body is mapped to correspond with a spatial or conceptual dimension of the information being conveyed. For example, vibrations on the left, middle, and right positions of an armband can…

Logical Navigation(also: Structural Navigation, Semantic Navigation)

A non-visual navigation strategy in which a user moves through a web page by its semantic structure — jumping between heading levels, ARIA landmarks, skip links, form fields, or other role-tagged regions — rather than reading the content sequentially or sampling fragments by…

Logical Reading Order(also: Reading Sequence, Programmatic Reading Order)

The sequence in which content within a document is presented to assistive technologies, which should match the intended logical flow of the content as a human reader would understand it. In PDFs, the logical reading order is determined by the tag tree structure, not the visual…

Logocentrism

In captioning studies, the systematic prioritization of speech and spoken language over non-speech sounds in captioning practices and technologies. Logocentrism in captioning manifests as speech captions receiving more attention, resources, and technical development than…

Lombard Effect(also: Lombard Reflex, Lombard Response)

The involuntary tendency of speakers to increase the intensity, duration, and fundamental frequency of their speech when communicating in noisy environments. Named after French otolaryngologist Étienne Lombard who first described the phenomenon in 1911, the effect involves…

Loneliness(also: Perceived Social Isolation)

The subjective feeling of being alone or disconnected from others, regardless of the actual quantity of social contacts a person has. Loneliness differs from social isolation in that it reflects perceived rather than objective social disconnection—a person can feel lonely in a…

Long Description(also: Extended Description, longdesc)

A detailed textual description of an image or other non-text content that goes beyond the brief summary provided by alt text. Long descriptions are used for complex images such as charts, diagrams, infographics, or detailed illustrations where a short alt text cannot convey all…

Long Tail(also: Long-tail Distribution, Long-tail Participation)

A statistical distribution in which a small number of items or participants account for the majority of the total, while a very long list of lower-frequency items collectively make up the remainder. The term was popularised by Chris Anderson in reference to online retail, but it…

Longdesc(also: Long Description, longdesc Attribute)

An HTML attribute historically used to provide extended descriptions for images that require more detail than can fit in an alt attribute. The longdesc attribute contained a URL pointing to a separate page or anchor with the full description. While part of HTML 4.01 and…

Longitudinal Study(also: Long-Term Study)

A research method that involves repeated observations or measurements of the same subjects over an extended period of time. In accessibility and reading support research, longitudinal studies are important for evaluating the sustained impact of interventions, tracking skill…

Look to Speak

A free Android application developed by Google Creative Lab that enables people with speech and motor impairments to communicate by selecting images or pre-written phrases using eye movements detected by the smartphone's front-facing camera. Users navigate by looking left,…

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,…

Loosely Coupled Interaction(also: Loosely Coupled Dual Interaction)

An interaction architecture in which two or more user interfaces share the same underlying content and data but operate independently through separate, non-overlapping input and output modalities. In a loosely coupled system, each interface is purpose-designed for its target…

Loss Aversion

A cognitive bias in which people experience the pain of losing something more intensely than the pleasure of gaining something of equal value. In the context of technology accessibility and aging, loss aversion significantly influences older adults' adoption of digital tools,…

Loss of Obscurity(also: Loss of anonymity)

A concept introduced by Thomas J. Carroll in his 1961 book "Blindness: What It Is, What It Does, and How to Live with It," in which he identified twenty distinct losses that accompany the onset of blindness. Loss of obscurity refers to the unavoidable conspicuousness of carrying…

Lost Generation

In ADHD and autism discourse, the term refers to adults — particularly women, minority genders, and people of colour — who went undiagnosed as children due to gendered diagnostic criteria, systemic medical bias, and the historical exclusion of non-white, non-male bodies from…

Loudness Recruitment(also: Recruitment, Hyperacusis-like Recruitment)

Loudness recruitment is a common consequence of sensorineural hearing loss in which the range between 'just audible' and 'uncomfortably loud' sounds is compressed — quiet sounds are harder to hear, but sounds above threshold grow louder more rapidly than in a typical listener.…

Low Bandwidth Input(also: Limited Input, Reduced Bandwidth Input)

A category of human-computer interaction where the user can only produce a very small number of distinct signals — typically one to four — when communicating with a computer. Low bandwidth input characterizes users with severe motor and speech impairments, such as those with…

Low Literacy(also: Limited Literacy, Functional Illiteracy)

A level of reading and writing ability that is below what is typically needed to function effectively in everyday situations requiring text comprehension. Low literacy may result from limited educational opportunities, learning disabilities, cognitive disabilities, or reading in…

Low Vision(also: Partial Sight, Visual Impairment)

A visual condition in which a person has significant vision loss that cannot be fully corrected with glasses, contact lenses, medication, or surgery, but retains some usable vision. People with low vision may have reduced visual acuity, limited field of vision, or difficulty…

Low Vision(also: Partial Sight, Partially Sighted)

A visual impairment that cannot be fully corrected by glasses, contact lenses, medication, or surgery, but where some usable vision remains. Low vision encompasses a wide range of conditions and severity levels, typically defined as visual acuity between 20/70 and 20/400 in the…

Low and Middle Income Countries(also: LMICs, Developing Countries, Global South)

A World Bank classification for countries with gross national income per capita below a defined threshold, encompassing low income and lower-middle income economies. In accessibility contexts, LMICs present distinct challenges including limited investment in accessible…

Low vision(also: Partial sight, Visual impairment)

A level of visual impairment that cannot be fully corrected with standard glasses, contact lenses, medication, or surgery, but retains some usable vision — distinguishing it from total blindness. Low vision encompasses a range of conditions affecting acuity, visual field,…

Low- and Middle-Income Countries(also: LMIC, LMICs, developing countries)

Countries classified by the World Bank as having lower gross national income per capita, typically facing greater resource constraints in healthcare, education, and technology infrastructure. In accessibility contexts, LMICs present unique challenges including limited…

Low-Barrier Access(also: Low-Barrier Technology)

Technology or services designed to minimize obstacles to initial use, including cost, setup complexity, training requirements, and technical prerequisites. Low-barrier access is particularly important for people with temporary or newly acquired disabilities who may need…