Glossary

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Profound and Multiple Learning Disabilities(also: PMLD, Profound Intellectual and Multiple Disabilities, PIMD)

Profound and multiple learning disabilities (PMLD) refers to a combination of profound intellectual disability with additional physical, sensory, or health impairments that together create extremely complex support needs. Individuals with PMLD typically require high levels of…

Progress Bar(also: Progress Indicator)

A UI element that visually communicates the proportion of a task, process, or timeline that has been completed. In media players it indicates playback position; in forms and wizards it signals completion across steps; in file transfers it shows elapsed progress. Accessibility…

Progress Tracking(also: Progress Indication, Progress Visualization)

The use of visual or auditory indicators to show how far a user has advanced through a task, document, or process. In cognitive accessibility, progress tracking serves multiple functions: it provides a sense of accomplishment that motivates continued engagement, reduces anxiety…

Prompting System(also: Prompting Device, Task Prompting Technology)

An assistive technology that provides stepwise guidance through text, images, audio, or video instructions to help individuals complete multi-step tasks such as cooking, personal hygiene, or workplace activities. Prompting systems are widely used to support people with cognitive…

Prosopagnosia(also: Face Blindness)

A neurological condition characterised by the inability to recognise familiar faces, despite otherwise intact visual and cognitive abilities. People with prosopagnosia may fail to recognise family members, friends, or colleagues by face alone, instead relying on alternative cues…

Prospective Memory

The ability to remember to carry out intended actions in the future, such as taking medication at a specific time, attending an appointment, or completing a task when a particular cue arises. Prospective memory is distinct from retrospective memory (remembering past events) and…

Proxy(also: Support Person, Intermediary User)

In accessibility contexts, a person who assists someone with a disability in using technology or accessing services. Proxies may include family members, caregivers, support workers, or friends who help with tasks ranging from physical operation of devices to interpretation of…

Psycholinguistics

The scientific study of the cognitive and neural processes that underlie the production, comprehension, and acquisition of language. Psycholinguistic research measures phenomena such as reading and signing rate, comprehension under time pressure, lexical access, and the role of…

Read-Along(also: Read Along, Synchronised Highlighting, Karaoke-style Highlighting)

An accessibility pattern in which on-screen text is highlighted word-by-word or phrase-by-phrase in synchronisation with spoken audio. Used in children's reading apps, language-learning tools, accessible ebook formats (e.g., EPUB Media Overlays), and podcast players.…

Readability(also: Text Readability)

The ease with which written text can be read and understood, determined by factors including vocabulary complexity, sentence length, grammatical structure, and text organisation. Readability is distinct from legibility (which concerns the visual clarity of individual characters…

Readability formula(also: readability metric, readability index, readability measure)

A mathematical formula that estimates the difficulty of reading a text, typically based on features like sentence length, word length, syllable count, or vocabulary frequency. Common formulas include Flesch Reading Ease, Flesch-Kincaid Grade Level, SMOG, and Gunning Fog Index.…

Reading Assistance(also: Reading Assistance Technology, Reading Support Tools)

Reading assistance refers to technologies and strategies that help people understand written text more easily. This includes tools like text-to-speech, automatic text simplification, screen readers, reading rulers, and dictionary lookups. For accessibility, reading assistance is…

Reading Comprehension(also: Text Comprehension)

The ability to understand, interpret, and derive meaning from written text. Reading comprehension involves multiple cognitive processes including decoding words, activating background knowledge, making inferences, and monitoring understanding. It is a key target for reading…

Reading Fluency

The ability to read connected text accurately, at an appropriate pace, and with proper expression - distinct from word-level decoding skill on one side and from reading comprehension on the other. Fluency is typically measured along three dimensions: accuracy (proportion of…

Reading Level(also: Grade Level, Reading Grade Level)

An estimate of the education or skill level a reader needs to understand a text, usually expressed as a U.S. school grade (e.g., grade 4) or an equivalent band. Reading level is the target output of most readability formulas and automatic readability assessment systems, and it…

Redundancy Principle

A principle from the Cognitive Theory of Multimedia Learning stating that people learn better from graphics and narration than from graphics, narration, and on-screen text presenting the same words, because presenting identical information in both spoken and written form…

Rejection Sensitivity(also: Rejection Sensitive Dysphoria, RSD)

An intense emotional response to perceived or actual rejection, criticism, or failure that is commonly experienced by neurodivergent individuals, particularly those with ADHD and autism. Rejection sensitivity can significantly impact job-seeking behaviour, as the fear of…

Reminiscence(also: Reminiscing, Life Review)

The process of recalling and sharing past experiences, often prompted by sensory cues like photographs, music, or familiar objects. For people with dementia, reminiscence can be more accessible than discussing current events because long-term memories are often better preserved…

Reminiscence Therapy(also: Reminiscence-Based Therapy, Life Review Therapy)

A non-pharmacological therapeutic approach for people with dementia that uses artifacts, photographs, music, and other personally meaningful materials to stimulate recall of past experiences and prompt conversation about life events. Reminiscence therapy aims to maintain the…

Repair Mechanism(also: Conversational Repair)

In conversational interface design, a feature that helps the user and the system recover from misrecognition, ambiguity, or misunderstanding — for example, clarification prompts ("Did you mean the [X] cricket match?"), visible candidate lists, or "try again" affordances that…

Repetitive Questioning(also: Perseverative Questioning)

A behavioural symptom of dementia, particularly Alzheimer's disease, in which a person repeatedly asks the same question over and over, often within short time intervals. Repetitive questioning can stem from short-term memory loss (not remembering the answer or having asked),…

Resilience(also: Psychological resilience, Dementia resilience)

Resilience refers to the dynamic capacity of an individual to adapt positively in the face of adversity and to maintain or recover a satisfactory level of psychological and functional well-being. In the context of dementia, resilience challenges deficit-based models that frame…

Response Bias(also: Acquiescence Bias, Yea-Saying Bias)

A systematic tendency for research participants to respond in a particular way regardless of the actual content of the question, distorting data collection and analysis. In accessibility research involving people with intellectual disabilities, acquiescence bias — the tendency…

Route Knowledge(also: Procedural Knowledge, Sequential Knowledge)

Route knowledge is a type of spatial understanding that consists of sequential, turn-by-turn information about how to get from one place to another along a specific path. In navigation for people with disabilities, route knowledge is what most GPS apps provide — step-by-step…

Route Learning(also: Route Familiarization)

The process by which a traveler — particularly a blind or low-vision person — acquires a mental representation of a specific path through an environment, including its turns, landmarks, distances, surface changes, and points of interest. Route learning is a core component of…

SMOG(also: SMOG Index, SMOG Grade, Simple Measure of Gobbledygook)

A readability formula developed by G. Harry McLaughlin in 1969 that estimates the years of education needed to understand a text, based on the number of polysyllabic words (three or more syllables) in a fixed sample of sentences. SMOG is widely used in healthcare communication…

Safe Walking Technology(also: Safe Walking Aids, Walking Safety Devices)

Assistive technologies designed to help people with cognitive impairments, particularly dementia, walk safely outdoors. These devices typically combine GPS tracking, navigation assistance, fall detection, and emergency communication features. Safe walking technology aims to…

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…

Sans-Serif Font(also: sans serif, grotesque font)

A typeface that lacks the small projecting lines (serifs) at the ends of letter strokes. Sans-serif fonts like Arial, Helvetica, and Verdana are generally recommended for screen readability and are often preferred for users with dyslexia. Research shows sans-serif fonts lead to…

Satisficing

A decision-making strategy where users select the first option that appears "good enough" rather than evaluating all possibilities to find the optimal choice. Coined by Herbert Simon, satisficing is common in web navigation, especially among older adults and users with cognitive…

Scaffolding(also: Instructional Scaffolding, Cognitive Scaffolding)

A support strategy that provides temporary, structured assistance to help a learner accomplish tasks they cannot yet perform independently. In digital accessibility, scaffolding can take the form of progressive disclosure, step-by-step guidance, contextual help, or adaptive…

Scenario-Based Evaluation(also: Path-Based Testing, User Journey Testing)

An accessibility evaluation approach that assesses the complete user experience across a sequence of steps needed to accomplish a task, rather than testing individual pages in isolation. For example, evaluating an e-commerce checkout means testing every step from product search…

Schema(also: Script, Mental Schema, Cognitive Schema)

A cognitive framework or mental model that organises knowledge about a typical sequence of events in a familiar situation. In accessibility and AAC design, schemas are used to structure interfaces so that prestored messages or navigation options mirror the expected progression…

Schizophrenia(also: Schizophrenia Spectrum Disorders)

A chronic psychiatric condition characterized by disturbances in thought, perception, emotion, and behavior, including symptoms such as hallucinations, delusions, disorganized thinking, reduced emotional expression, and cognitive difficulties with memory, attention, and…

Scotopic Sensitivity(also: Irlen Syndrome, Visual Stress, Meares-Irlen Syndrome)

A visual-perceptual condition in which certain wavelengths of light cause discomfort, distortion, or difficulty when reading. People with scotopic sensitivity may experience text appearing to shimmer, move, or blur on the page, particularly with high-contrast black text on white…

Selective Attention(also: Focused Attention)

The cognitive ability to focus on a specific stimulus or task while filtering out irrelevant distractions. In accessibility and inclusive design, understanding selective attention is critical for creating interfaces that minimize cognitive overload, reduce visual clutter, and…

Self-Motivation

Self-motivation is the internal capacity to initiate and sustain tasks without relying on external rewards or pressure. In accessibility contexts, self-motivation is relevant to executive function and is often reduced for people with ADHD, depression, chronic fatigue, and…

Self-Regulated Learning(also: SRL, Self-Directed Learning)

The process by which learners actively manage their own cognition, motivation, and behavior to achieve learning goals. Self-regulated learning involves planning approaches, monitoring comprehension, adjusting strategies when needed, and evaluating outcomes. Research shows that…

Self-Regulation(also: Self-Management, Behavioral Regulation)

The ability to monitor and manage one's own emotions, behavior, and cognitive processes to achieve goals. Self-regulation encompasses emotional regulation, attentional control, and behavioral inhibition. In accessibility contexts, designing for self-regulation means creating…

Self-Scaffolding

Self-scaffolding is a process in which learners independently create their own support structures to achieve objectives they would not have reached without that support. Unlike traditional scaffolding, which is provided by teachers or designed into tools, self-scaffolding…

Semantic Accessibility

An approach to web accessibility that focuses on the predictability and consistency of user interface behavior, layout, and interaction patterns rather than the underlying code. Semantic accessibility ensures that similar elements appear in the same locations across pages, menus…

Semantic Relatedness(also: Semantic Similarity, Semantic Association)

A measure of how closely related two words or concepts are in meaning, encompassing various types of relationships including synonymy, hyponymy, meronymy, and general topical association. In assistive technology, semantic relatedness is used to improve word prediction and…

Sense of Agency(also: User Agency, Personal Agency)

The subjective experience of being in control of one's own actions and their effects on the external world. In accessible design, supporting sense of agency means ensuring users feel empowered to make choices, initiate interactions, and influence outcomes rather than being…

Sensory Integration(also: Sensory Processing, SI)

The neurological process of organizing sensory information from the body and environment to produce appropriate responses. Sensory integration dysfunction (also called sensory processing disorder) occurs when the brain has difficulty processing and responding to sensory input,…

Sensory Overload(also: Sensory Overwhelm, Overstimulation)

A state in which the brain receives more sensory input than it can effectively process, leading to stress, anxiety, difficulty concentrating, and in severe cases, meltdowns or shutdowns. Sensory overload can be triggered by excessive visual complexity, noise, crowds, bright or…

Sensory Processing Sensitivity(also: SPS, Sensory Processing Differences)

Sensory Processing Sensitivity refers to differences in how an individual perceives, filters, and responds to sensory input across modalities such as vision, sound, touch, taste, and proprioception. It is commonly elevated in autistic people, but also occurs in people with ADHD,…

Sensory overload(also: Sensory overstimulation, Overstimulation)

A state in which the brain receives more sensory input than it can effectively process, leading to feelings of overwhelm, distress, anxiety, or shutdown. Sensory overload is particularly common among autistic individuals and people with sensory processing differences, but can…

Serious Game(also: Serious Games, Applied Game)

A game designed for a primary purpose beyond entertainment, such as education, training, health intervention, or cognitive rehabilitation. In accessibility and healthcare contexts, serious games are used to support people with conditions like ADHD by targeting specific cognitive…

Shared Reality(also: Shared Realities)

Shared reality is the experience of a common inner state - thoughts, feelings, or perceptions about an object or situation - between two or more people, established through communication and mutual acknowledgement. In dementia care and accessibility research, sustaining shared…

Short-Form Video Content(also: SFVC, Short-Form Content, SFC)

Brief video content, typically 15–60 seconds long, presented in portrait orientation and consumed via infinite vertical scroll on platforms such as TikTok, Instagram Reels, YouTube Shorts, Facebook Reels, and Douyin. The format has become an important information and community…