Glossary

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Print Illiteracy(also: Alipi)

A condition where a literate person is unable to meaningfully access or use written web content, not because they cannot read, but because the content is presented in a language, script, or format they do not understand. Print illiteracy distinguishes itself from traditional…

Printed Circuit Board(also: PCB)

A printed circuit board (PCB) is a flat board, typically made of fibreglass-reinforced epoxy laminate with copper traces, that mechanically supports and electrically connects electronic components. PCBs are the standard substrate of nearly all modern electronics, from consumer…

Prior Authorization(also: Pre-Authorization, Pre-Auth, PA)

A requirement by health insurance companies that a healthcare provider obtain approval before a prescribed medication or treatment is covered. Prior authorization processes often involve multi-step bureaucratic procedures — submitting documentation, waiting for review, handling…

Prior Knowledge(also: Background Knowledge, Existing Knowledge)

Information and experience a user brings to a technology interaction before it begins, including technical knowledge of how devices work, functional knowledge of task goals, strategic knowledge of problem-solving approaches, and self-knowledge of personal abilities and…

Privacy

The right and practical ability of a person to control the collection, use, and disclosure of information about themselves, their body, their activities, and their relationships. For accessibility, privacy intersects with disability in specific ways: assistive-technology usage…

Privacy Alert(also: Privacy Notification, Privacy Warning)

A notification informing users about the potential presence of private or sensitive content in their captured images or video. Privacy alerts aim to prompt users to apply obfuscation or take other protective action. However, research with blind users highlights tensions: while…

Privacy Enhancing Technology(also: PET, PETs)

A category of tools, protocols, and practices designed to protect user privacy while using digital systems, including anonymising proxies, tracker blockers, end-to-end encryption, differential privacy, and private browsing modes. PETs increasingly intersect with accessibility…

Privacy Leak(also: Accidental Disclosure, Privacy Disclosure)

The unintentional capture and sharing of sensitive personal information through visual assistance technologies. Research has found that approximately 10% of images submitted to VAT services contain private content such as pregnancy tests, prescription medication, and people,…

Privacy Threat Model(also: Privacy Threat Analysis, Privacy Risk Assessment)

A systematic process for identifying, classifying, and evaluating potential privacy risks that a technology system may pose to its users. Privacy threat modeling extends security-focused frameworks (like Microsoft's STRIDE) to address privacy-specific concerns. The LINDDUN…

Privacy by Default(also: Privacy by Design, Default Privacy Settings)

Privacy by default is a design principle requiring that systems automatically protect user privacy without requiring users to take action. In accessibility contexts, this principle is particularly important for older adults and people with cognitive disabilities who may not…

Privacy by Design(also: PbD)

A framework that embeds privacy protections into the design and architecture of systems and business practices from the outset, rather than adding them as afterthoughts. In the context of visual assistance technologies, privacy by design encompasses on-device processing, data…

Privacy-Enhancing Data Filters(also: Privacy Filters, Data Obfuscation Filters)

Visual or data modifications applied to training datasets that obscure the identity of contributors while preserving the information needed for machine learning tasks. In the context of sign language video, these filters may include face blurring, cel shading, avatar…

Privacy-Enhancing Technologies(also: PETs)

Tools and techniques that protect user privacy by limiting the collection, use, and dissemination of personal information online. Examples include VPNs, ad blockers, privacy-focused browsers like Brave, encrypted messaging apps, and Do Not Track settings. For users with…

Private Visual Content(also: PVC, Visual Privacy)

Private visual content (PVC) refers to visual information in images or videos that the person depicted or sharing the content considers private and would not want publicly disclosed. For people who are blind using visual interpreter services, PVC is a particular concern because…

Proactive Prompt(also: Proactive Cue)

In voice-interface and conversational-agent design, a system-initiated utterance or visual cue that surfaces a suggestion, reminder, or next step without the user first asking. Examples include suggesting the weather at a user's usual wake-up time, reminding someone to take…

Proactive description(also: Proactive notification, Unsolicited description)

The ability of an assistive system to automatically provide relevant visual or environmental information without requiring the user to explicitly request it. For blind and visually impaired users navigating real-world environments, proactive description is critical — a human…

Probabilistic Sampling(also: Random Sampling, Statistical Sampling)

A sampling method in which every member of a population has a known, non-zero probability of being selected for the sample. In accessibility evaluation, probabilistic sampling of web pages allows auditors to make statistically valid generalisations about the overall…

Probing(also: Link Probing, Exploratory Browsing)

Probing is a browsing behavior where a user follows a link to see where it leads and then immediately returns to the previous page. It is commonly observed among blind and screen reader users as a coping strategy when the link text or surrounding context does not provide enough…

Problem-Solving Style(also: Problem-Solving Facets, GenderMag Facets)

Problem-solving style refers to the characteristic ways individuals approach technology-mediated problem-solving tasks. In inclusive design, particularly in the GenderMag method, problem-solving style is captured across five facets: Motivations (why someone uses technology),…

Procedural Accessibility

An aspect of web accessibility that addresses the consistency and clarity of interaction sequences and workflows within digital systems. Procedural accessibility ensures that similar services follow the same patterns of interaction — for example, all online purchasing processes…

Procedural Fairness(also: Procedural Justice)

Procedural fairness (also called procedural justice) refers to the perceived fairness of the processes through which decisions are made, as distinct from the fairness of outcomes. In the context of digital platforms and content moderation, it encompasses three key dimensions:…

Procedural Feedback System(also: Process-Oriented Guidance System)

An assistive technology paradigm that provides dynamic, step-by-step support throughout complex multi-step tasks rather than addressing isolated moments of need. Unlike traditional assistive tools that help with discrete actions (e.g., identifying a color or reading a label),…

Procedural Task Tracking(also: Task Progress Tracking, Step Tracking)

The automated monitoring of a user's progress through a multi-step task, identifying which steps have been completed, which are in progress, and which remain. In accessibility contexts, procedural task tracking enables assistive systems to provide context-sensitive guidance…

Procedural task analysis(also: Task decomposition, Step-by-step analysis)

A method of breaking down complex tasks into sequential, discrete steps to understand user workflows and identify points of difficulty. In accessibility contexts, procedural task analysis reveals where users with cognitive, sensory, or motor impairments encounter barriers — such…

Process Model of Emotion Regulation(also: Gross Process Model)

A theoretical framework developed by James Gross that conceptualizes emotion regulation as a dynamic, continuous process with four main stages: identification (recognizing an emotion that needs regulation), selection (choosing a regulation strategy such as situation selection,…

Processing Speed(also: Information Processing Speed, Cognitive Processing Speed)

A cognitive ability referring to how quickly a person can perceive, process, and respond to information. Processing speed affects how rapidly someone can read, understand instructions, react to stimuli, and complete timed tasks. It naturally declines with age, beginning in…

ProcureAccess(also: Procure Access)

A business-to-business initiative run by the non-profit Disability:IN that asks organisations to commit to embedding accessibility and disability inclusion into their technology procurement processes. Signatories pledge to require accessibility conformance information (such as…

Product Identification(also: Product Recognition)

The task of determining what a packaged or unpackaged product is from visual (or other sensory) input, at a level of detail useful to an end user: generic type (soup, cereal, shampoo), brand (Campbell's, Kellogg's, Dove), and variety or flavour (tomato vs. chicken noodle; 90%…

Product Manual(also: Instruction Manual, User Manual, OEM Manual)

The documentation shipped with a consumer product that explains how to assemble, operate, and troubleshoot it. Product manuals come as paper booklets, fold-out sheets, PDFs, web pages, or occasionally audio. They are a chronic accessibility problem for blind and low-vision users…

Productivity Norms(also: Compulsory Productivity)

Socially constructed expectations about the quantity and pace of work output that individuals should maintain. Productivity norms are often built around non-disabled bodies and minds, creating barriers for people with disabilities whose work patterns, energy levels, or…

Professional Development(also: Continuing Education, In-service Training)

Ongoing learning activities that professionals undertake to maintain and improve their skills throughout their careers. For accessibility professionals and special educators, professional development includes workshops, conferences, online courses, peer mentoring, and…

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…

Programming Accessibility(also: Accessible Programming, Accessible IDE)

The practice of making software development tools, environments, and workflows usable by programmers with disabilities. Programming presents unique accessibility challenges beyond general computer use: code requires precise typing of special characters and symbols, specific…

Programming by Demonstration(also: PBD, Record and Replay, Macro Recording)

A technique for creating automated sequences of actions by recording a user performing the task manually, rather than requiring the user to write code or scripts. The system observes the user's interactions (clicks, keystrokes, form inputs) and generates replayable instructions.…

Programming by Example(also: PBE, Programming by Demonstration)

A technique in end-user programming where a system infers a generalizable program from concrete examples provided by the user, rather than requiring the user to write code directly. In accessibility contexts, programming by example has been used to enable nonprogrammers to…

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…

Progressive Disability(also: Degenerative Condition, Progressive Condition)

A disability or condition that worsens over time, requiring adaptive strategies and technologies that can evolve with changing abilities. Progressive disabilities such as dementia, multiple sclerosis, and muscular dystrophy pose unique design challenges because assistive…

Progressive Disclosure(also: Staged Disclosure, Layered Interface)

An interaction design pattern that initially presents only the most essential options or information, revealing additional complexity progressively as users need or request it. Progressive disclosure reduces cognitive load and visual clutter by avoiding overwhelming users with…

Progressive Enhancement

A web design strategy that starts with a baseline of essential content and functionality that works in any browser or with any internet connection, then layers on enhanced features for users with more capable browsers or greater bandwidth. Rooted in the "graceful transformation"…

Project Gutenberg

The oldest mass digital-library project, founded by Michael Hart in 1971, offering tens of thousands of public-domain ebooks in plain text, HTML, and EPUB. Project Gutenberg titles are widely used as a free accessible-text source by people with print disabilities, and its…

Project Sidewalk

An open-source web-based crowdsourcing tool developed at the University of Washington that enables volunteers to virtually audit sidewalk accessibility using Google Street View panoramas. Contributors label four types of accessibility features and problems: curb ramps, missing…

Proliferative Diabetic Retinopathy(also: PDR)

An advanced stage of diabetic retinopathy in which abnormal new blood vessels grow on the retina, causing bleeding, scarring, and progressive vision loss that can include blurred vision, floaters, dark spots, and partial or complete blindness. A major cause of acquired low…

Prolific

An online participant recruitment platform used in academic research that allows researchers to screen and recruit participants based on demographic criteria including disability status. Prolific and similar platforms (such as Amazon Mechanical Turk) have been increasingly used…

Prompt Chaining(also: Chained Prompting, Sequential Prompting)

A technique for interacting with large language models where multiple prompts are issued in sequence, with each prompt building on the output of the previous one to achieve a more refined or accurate result. In accessibility and bias mitigation contexts, prompt chaining enables…

Prompt Contradiction

A type of large language model failure in which the system disregards explicit instructions or constraints given in the user prompt, producing output that contradicts what was asked. For example, an AI responding with visual instructions like "click the green button" after the…

Prompt Engineering(also: Prompt Design, Prompt Crafting)

The practice of designing and structuring input prompts to guide large language models (LLMs) toward producing more accurate, relevant, and useful outputs. In accessibility contexts, prompt engineering techniques such as role-play prompting (assigning expert personas),…

Prompt Injection(also: Indirect Prompt Injection, Prompt Engineering Attack)

A technique — originally an LLM security concern — in which carefully crafted instructions embedded in a user prompt or referenced content override the model's intended behaviour, constraints, or safety rules. In accessibility research and practice, the term is increasingly used…

Prompt engineering(also: Prompt design, Prompt crafting)

The practice of designing and iteratively refining natural language inputs to large language models to elicit more accurate, relevant, or useful responses. In accessibility contexts, prompt engineering is an emerging skill that enables disabled users to customise AI interactions…

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…