Glossary
Searchable terminology from accessibility, web standards, and related fields.
6660 terms — page 236 of 333
- Random Walk (Random Walk Sampling)
- In web-accessibility evaluation, a random walk is a probabilistic sampling method that starts from a seed page (typically the home page) and follows outgoing links according to a probability rule — fo…
- Randomization Test (Randomisation Test, Permutation Test)
- A randomization test (also called a permutation test) is a non-parametric statistical test that computes a p-value by re-shuffling the observed data many times under the null hypothesis and asking how…
- Range of Motion (ROM)
- The full extent of movement possible at a joint, measured in degrees of rotation or linear distance. Range of motion is a fundamental clinical measurement used by occupational and physical therapists …
- Range of Motion (ROM, Joint Mobility)
- The full movement potential of a joint, measured in degrees of a circle, from the starting position to maximum extension or flexion. Range of motion exercises are fundamental to physical rehabilitatio…
- Rapid Auditory Processing (RAP, Auditory Temporal Processing)
- The ability to perceive and process rapidly changing auditory signals that occur within tens of milliseconds, such as the rapid frequency and amplitude transitions that characterise speech sounds. Rap…
- Rapid Prototyping
- The fast fabrication of a physical model or functional prototype using computer-aided design and manufacturing technologies like 3D printing. In assistive technology development, rapid prototyping ena…
- Rapid Serial Visual Presentation (RSVP)
- A text display method in which words or short phrases are shown one at a time in a fixed location on screen in quick succession, eliminating the need for eye movements (saccades) between words. RSVP w…
- Ray Casting (Raycasting)
- An interaction technique in 3-D environments where an invisible ray is projected from a point (such as a user's finger position or controller) into the virtual scene to determine which object the ray …
- Re-identification risk (De-anonymization risk, Data re-identification)
- The possibility that an individual can be identified from supposedly anonymized data by combining multiple data points or matching against external datasets. People with disabilities face heightened r…
- Re-narration (Web Re-narration, Content Re-narration)
- The process of creating alternative versions of web content — such as translations, simplifications, audio descriptions, or culturally adapted media — to make it accessible to audiences who cannot eff…
- Re-speaking (Respeaking, Speech-to-Text Relay)
- A captioning technique in which a trained operator listens to a speaker and repeats (re-speaks) their words clearly into a high-quality microphone in a controlled environment, allowing automatic speec…
- Reach Envelope (Workspace Envelope, Reach Zone, Comfort Zone)
- The three-dimensional volume of space that a person can physically access with their hands or arms from a given position, taking into account their specific motor abilities, range of motion, and comfo…
- Reacher (Grabber, Reacher-Grabber, Grabber Tool)
- A reacher (also called a grabber or reacher-grabber) is a low-cost handheld assistive device — typically a lightweight aluminum or plastic shaft 60-90 cm long with a trigger handle at one end and a pa…
- Reaching Time (Navigation Time, Time to Target)
- A usability metric measuring the time required for a user to navigate to a specific element on a web page. For blind users employing screen readers, reaching time is a key indicator of page navigabili…
- Read-Along (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, accessi…
- Read-Aloud Technology (Read-Aloud Feature, Text Read-Aloud)
- Technology that converts written text to spoken audio output, allowing users to listen to content rather than or in addition to reading it visually. Read-aloud technology differs from general text-to-…
- Readability (Text Readability)
- The ease with which a reader can read and understand written text. Readability encompasses both visual readability (typography, layout, color contrast, spacing) and linguistic readability (vocabulary …
- Readability (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 distin…
- Readability formula (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 …
- Readily Achievable (Readily Achievable Barrier Removal)
- A legal concept from the Americans with Disabilities Act (ADA) meaning that barrier removal is easily accomplishable and able to be carried out without much difficulty or expense. What qualifies as re…