Glossary
Searchable terminology from accessibility, web standards, and related fields.
25 results found in Accessibility Evaluation.
- ABA Reversal Method (ABA Design, Reversal Design)
- The ABA reversal method is a single-subject experimental design in which one participant is observed across three phases: a baseline (A), an intervention (B), and a return to baseline (A). By comparin…
- Ability Heuristics
- A set of nine accessibility-focused design heuristics — Adaptability, Equitable Experience, Flexible Task Completion, Efficiency and Effectiveness of User Action, Multiple Modalities, Understandable M…
- Accessibility Barrier (A11y Barrier)
- Any aspect of a digital product, web page, document, or service that prevents or impedes a person with a disability from perceiving, operating, understanding, or using it on an equivalent basis to som…
- Accessibility Inspection (Accessibility Inspection Method, Accessibility Audit)
- An evaluation approach in which an expert or designer reviews an interface against a set of accessibility criteria without recruiting end users, analogous to usability inspection methods such as heuri…
- Accessibility Internet Rally (AIR, AIR-Austin)
- An annual web-development competition run by Knowbility (based in Austin, Texas) in which teams of developers are paired with non-profit clients and judged partly on the accessibility of the websites …
- Algorithmic Audit (AI Audit, Algorithmic Auditing)
- A structured evaluation of an algorithmic system that measures how its behaviour differs across users, groups, or contexts - typically to surface bias, fairness failures, or disparate impact. Accessib…
- Checkpoint (WCAG Checkpoint, Success Criterion, Accessibility Checkpoint)
- A checkpoint is a specific, testable accessibility requirement in a set of guidelines — for example, 'provide a text equivalent for every non-text element' is WCAG 1.0 checkpoint 1.1. The term is stro…
- Dunning-Kruger Effect
- A cognitive bias in which people with limited knowledge or competence in a domain overestimate their ability, while those with greater expertise tend to underestimate their relative skill. In accessib…
- Error Profile (Accessibility Error Profile, Violation Profile)
- An error profile is a structured summary of the accessibility issues detected on a page, typically represented as a numeric vector with one component per checkpoint or rule — counts of violations, bin…
- Failure Mode (Accessibility failure mode)
- In accessibility evaluation, any hindrance caused by a product or web site that prevents a user with a disability from achieving a goal with the same effectiveness, efficiency or safety as a non-disab…
- Failure Rate (FR (accessibility metric))
- An accessibility metric introduced by Sullivan and Matson (2000) that, for a given page and a given checkpoint, divides the number of checkpoint violations found by the maximum number of violations th…
- Functiona11ity Error (Functionality Error, Functiona11ity)
- A term coined by Zhong et al. (2026) — a portmanteau of 'functionality' and 'a11y' (accessibility) — for an accessibility barrier that only manifests through interaction. The static state of the UI ap…
- Heuristic Walkthrough (Heuristic walk-through)
- A usability evaluation method proposed by Andrew Sears (1997) that combines scenario-based cognitive walkthrough with heuristic evaluation. Evaluators work through realistic user tasks using a priorit…
- Listenability (Auditory Readability, Speech-Output Quality)
- A web-accessibility usability metric that measures how appropriate a page's rendered text is when read aloud by a screen reader or voice browser — complementary to, and distinct from, raw WCAG conform…
- Navigability (Ease of Navigation, Web Navigability)
- The ease and efficiency with which a user can move through a web page, application, or document to reach their intended content. For accessibility practice, navigability is a primary determinant of wh…
- OPTIMAL-EM (Optimised Evaluation Methodology)
- A web accessibility evaluation methodology proposed by Hambley, Yesilada, Vigo, and Harper to complement the W3C's WCAG-EM by providing a statistically grounded, complexity-driven method for selecting…
- 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…
- Representative Sampling (Representative Page Sampling)
- In web accessibility auditing, the practice of selecting a subset of pages from a website that statistically reflects the full site, so that evaluation findings can be generalised to pages not directl…
- Sampling Method (Sampling, Page Sampling, Site Sampling)
- A sampling method is a rule for selecting a subset of pages, screens, or components from a larger product to be evaluated for accessibility. Because full manual evaluation of every page on a real-worl…
- Small-n Experimental Design (Small-sample Design, Single-case Design)
- Small-n (or single-case) experimental design is a family of research methodologies aimed at drawing rigorous causal conclusions from very few — sometimes just one — participants. The approaches includ…