Web Testing Usability Heuristics

Web Usability Testing — Heuristic Evaluation Methodology

Full methodology for web-usability-tester: how to evaluate a live site's first-time comprehension against established usability science, without reading specs, source, or mockups.

Reference Modules

• reference/01-why-this-agent-exists-and-inputs.md — why this agent exists, invocation inputs.
• reference/02-spec-blind-discipline.md — the Spec-Blind Discipline (hard rule).
• reference/03-relationships-and-nondestructive-constraint.md — relationship to web-exploratory-tester/web-design-tester/swe-ui-checker, the Non-Destructive Constraint.
• reference/04-heuristic-evaluation-and-walkthrough.md — Nielsen's 10 heuristics, the cognitive-walkthrough four questions, first-click/information-scent analysis, the naive-user stance.
• reference/05-usability-dimensions-checklist-part1.md and reference/06-usability-dimensions-checklist-part2.md — the full dimensions checklist (predictability, consistency, information scent, edge states, error prevention, cognitive load, affordance, etc.).
• reference/07-mandatory-probes-a-b-c.md and reference/08-mandatory-probe-d-and-url-naturalness.md — the four Mandatory Systematic Probes (conditional-control discoverability, jargon scan, cross-view redundancy, unit/currency consistency) and URL Naturalness.
• reference/09-responsive-usability.md — Responsive Usability at mobile/tablet/desktop.
• reference/10-browser-driving.md — how to drive the browser (WebFetch/curl/Playwright).
• reference/11-suggesting-new-behaviour-for-specs.md — how to propose spec-suggestions.md entries without breaking the spec-blind stance.
• reference/12-finding-anatomy-and-severity.md — the full UWT-### finding anatomy and the Nielsen 0-4 severity scale.
• reference/13-output-modes-overview.md and reference/14-output-mode-plan-and-delivery.md — the output-mode selection table and the plan/delivery modes' document sets.
• reference/15-output-mode-localtmp-procedure-and-quality.md — the local-tmp mode, the 11-step procedure summary, and quality guidelines.
• reference/16-constraints.md — hard constraints.

Core Principles

Stay blind, always. The moment the evaluator learns the intended behaviour, first-time comprehension can no longer be judged — never read specs/**, source, or mockups to decide what is "correct". Cite the principle, never a vibe — every finding names the heuristic, walkthrough question, UX law, or WCAG criterion it violates; no principle, no finding. Enumerate, never sample — the four Mandatory Systematic Probes exist because a heuristic sweep reads past exactly these failure classes once the evaluator has already explored the page.

Related

web-exploratory-tester (the spec-aware functional/correctness sibling), web-design-tester (the design-aware third lens of the live-site advocate triad), plan-creating-project-plans (explicit plan-mode structure), plan-writing-gherkin-criteria (Gherkin ACs and spec-suggestions.md scenarios), docs-applying-content-quality.