Design for equal task capability.
Ensure all users can complete core tasks, not merely access interface elements.
Contents 5. Visual Communication 4. Accessibility
Whether content can be perceived by all users.
First, ask yourself
“Can users with varied abilities perceive and act effectively in your system?”
Mission statement
Ensure all users can perceive and use the system by accommodating diverse abilities without exclusion.
Key heuristics Accessibility
- All users must be able to complete core tasks, not just reach interface elements.
- Design must assume wide sensory, motor, and cognitive variability.
- Accessible workflows must provide equivalent capability.
- State, options, and outcomes must be clearly distinguishable.
- No essential information may rely on a single sensory channel.
- Visual, auditory, tactile, and keyboard-based input must be supported comparably.
- Keyboard, screen reader, and touch interaction must be designed as primary, not secondary.
- Dynamic and automated content must remain operable and legible.
- Accessibility must persist under fatigue, distraction, and urgency.
Executive brief
The system must ensure all users can perceive, distinguish, and act.
Core questions Accessibility
“Can people with different abilities use the system in real-world conditions?”
“Is it usable in practice, not just in theory?”
Focus areas
Stress-first
“Does the system still work under fatigue, distraction, or limited mobility?”
“Can it be used in a hurry or with one hand?”
Equity-first
“Who might be excluded by this design?”
“What assumptions about ability are built in?”
Capability-aware
“Are perception, operation, and understanding all supported?”
“Do accessible paths offer equal capability, not just basic access?”
AI-aware
“Does adaptive behavior maintain accessibility?”
“Are generated content and controls accessible by default?”
UX directives Accessibility
Design for human variability as a baseline condition.
Account for a wide range of sensory, motor, and cognitive differences.
Ensure accessible workflows are functionally equivalent.
Prevent degraded or secondary experiences for alternative access paths.
Make state and consequence clearly distinguishable.
Design perceptible differentiation for actions, options, and outcomes.
Do not rely on a single sensory channel.
Ensure focus, state, and feedback are perceivable across modalities.
Provide multimodal interaction paths.
Support visual, auditory, tactile, and keyboard-based input equivalently.
Treat alternative input methods as primary.
Design keyboard, screen reader, and touch interaction with equal priority.
Ensure dynamic and automated content remains accessible.
Preserve operability and legibility in changing or AI-driven interfaces.
Design accessibility for real-world conditions.
Ensure usability persists under fatigue, distraction, and urgency.
Executive summary
- Accessibility is equal task capability, not optional accommodation.
- It assumes human variability as a baseline condition of design.
- The system must provide functionally equivalent workflows across sensory and input modalities.
- State, feedback, and consequence must be perceivable without reliance on a single channel.
- Dynamic and automated behaviors must remain operable under varied real-world conditions.
- Accessibility succeeds when all users can complete core tasks with dignity, clarity, and independence.
Success indicators
- All users can complete core tasks successfully.
- Important information and actions are clearly distinguishable.
- The interface does not rely on a single sensory channel.
- Users can interact using different input methods.
- The system remains usable under varied conditions and abilities.
One-line summary
Before a system can serve everyone, it must account for human variation.