Accessibility Glossary

Users perceive aesthetically pleasing designs as more usable — even when they're not. Beautiful design builds tolerance for minor friction. But aesthetics can't compensate for fundamental accessibility failures.

Too many options leads to decision paralysis and reduced satisfaction (paradox of choice). Limit visible options, use defaults, and allow filtering. Directly overlaps with cognitive load reduction.

Productivity soars when response time is under 400ms. Interactions that feel instant maintain flow state. Use skeleton screens, optimistic UI, and progress indicators when latency exceeds this threshold.

Time to reach a target = f(distance, size). Larger, closer targets are faster to hit. Make primary actions big and near the cursor. Applies directly to target size accessibility (WCAG 2.5.8).

Total immersion in a task where challenge matches skill. Design for flow: minimize interruptions, provide clear goals, give immediate feedback, and remove unnecessary friction. Accessibility barriers break flow.

Motivation increases as you approach a goal. Progress bars, step counters, and 'almost there' messaging accelerate completion. Loyalty cards that start pre-stamped outperform empty ones.

Decision time increases with the number and complexity of choices. Reduce options, use progressive disclosure, break complex tasks into steps. Directly supports cognitive accessibility.

Users spend most time on other sites — they expect yours to work the same way. Leverage familiar patterns (nav on top, logo links home, search in header). Novelty has a cost.

Elements sharing a bounded area are perceived as grouped (Gestalt). Cards, sections, fieldsets — boundaries create relationships without needing proximity alone. Supports info & relationships (WCAG 1.3.1).

Objects near each other are perceived as a group (Gestalt). Use spacing to create visual relationships — related form fields close together, unrelated sections further apart. Replaces the need for borders.

People interpret complex images as the simplest form possible. Reduce visual noise, favor clean geometry, and avoid ambiguous layouts. The brain seeks order — give it order.

Similar elements (shape, color, size) are perceived as related (Gestalt). Consistent styling for all buttons, all links, all headings. Breaking similarity draws attention — use intentionally for emphasis.

Visually connected elements (lines, arrows, shared color) are perceived as more related than disconnected elements. Breadcrumbs, step indicators, and flow diagrams leverage this principle.

Users carry compressed expectations of how systems work. Mismatches between mental models and actual behavior cause errors and frustration. Research reveals models; design should align with them, not fight them.

Working memory holds ~7 (±2) items. Chunk information into groups of 3–5. Phone numbers, card numbers, and step indicators all use chunking. Especially critical for users with cognitive disabilities.

The simplest solution is usually the best. Among designs that solve the problem equally well, prefer the one with fewer elements, fewer steps, and less cognitive overhead. Simplicity is a feature.

Users never read manuals — they start using software immediately. Design for exploration, not instruction. Progressive disclosure, inline help, and sensible defaults serve active users.

80% of effects come from 20% of causes. Focus on the 20% of features, flows, and pages that serve 80% of users. In accessibility: fixing the 6 most common WCAG failures addresses 96% of detected errors.

Tasks expand to fill available time. Reduce form fields and you reduce completion time. Set clear expectations with time estimates. Constrained interfaces (character limits, deadlines) drive efficiency.

Experiences are judged by their peak intensity and their ending — not the average. Invest in delightful success states and smooth offboarding. A painful checkout overshadows good browsing.

Be liberal in what you accept, conservative in what you send. Accept varied input formats (dates, phone numbers, spaces in card numbers). Output clean, consistent, predictable interfaces.

People focus on stimuli relevant to their current goal and filter out the rest. Important information must be visually prominent — not hidden in dense layouts. Banner blindness is selective attention at work.

People best remember the first (primacy) and last (recency) items in a series. Place key actions and navigation at the start and end of lists. Mobile bottom tabs leverage recency.

Every system has irreducible complexity. The question is who bears it — the user or the system. Good design absorbs complexity so users don't have to. Autocomplete, smart defaults, and wizards are examples.

The item that differs from the rest is most remembered (isolation effect). Highlight CTAs, error states, and new features by making them visually distinct. But don't rely on color alone (WCAG 1.4.1).

The cognitive system that temporarily holds information needed to complete tasks. Limited to ~4 chunks. Reduce reliance on memory: show don't recall, persist state, and keep related info visible together.

People remember incomplete tasks better than completed ones. Progress indicators, partially filled profiles, and onboarding checklists leverage this to drive completion. Use ethically — not as a dark pattern.