ux-heuristics

Walk through the interface checking each of Nielsen's 10 heuristics, such as system status visibility, error prevention, and consistency. Rate each issue found on a 0-4 severity scale based on frequency, impact, and persistence, then prioritize fixes starting with severity 3-4 issues.

They are ten general principles for interaction design: visibility of system status, match with the real world, user control and freedom, consistency, error prevention, recognition over recall, flexibility, minimalist design, error recovery, and help documentation. They serve as a checklist for finding usability problems without user testing.

Run heuristic evaluation first, before user testing, since it takes only 1-2 hours and catches major violations cheaply. Follow with user testing (2-4 hours) to observe real behavior, then use A/B testing or analytics for ongoing optimization.

Use a 0-4 scale: 0 is not a problem, 1 is cosmetic, 2 causes minor delays, 3 causes significant task failure, and 4 prevents task completion entirely. Consider three factors together: how often the issue occurs, how severe its impact is, and whether it is a one-time or persistent problem.

Dark patterns are interface designs that trick users into unintended actions, such as forced continuity, hidden costs, confirmshaming, and fake urgency. They violate usability heuristics deliberately and are increasingly illegal under GDPR, FTC rules, and the California Privacy Rights Act.

WCAG 2.1 Level AA requires a minimum 4.5:1 contrast ratio for normal text and 3:1 for large text (18pt or larger). UI components and interactive elements also need at least 3:1 contrast against adjacent colors.