Unit 1 · Lesson 3 of 20
Who can complete the task?
Identify barriers created by abilities, environment, and channel assumptions.
01 / Learn
The idea
Accessibility is part of task completion, not a final visual check. A person may be unable to see color differences, hear a prompt in noise, reach a control, use touch precisely, read the displayed language, or maintain attention during a timeout. These constraints can be permanent, temporary, or situational, and several can occur together.
Review each essential step by asking how a person perceives information, operates the control, understands the result, and recovers from error. Offer more than one usable way to receive critical information when the setting requires it. Do not assume that adding an audio prompt solves every visual barrier: the entrance may be loud, and private information may be unsafe to announce aloud.
One alternate format makes an experience accessible to everyone. Alternatives must match the task and be tested with people who use them.
02 / See the reasoning
Worked example
Fictional scenario
A museum ticket kiosk gives directions through color and spoken prompts while visitors stand in a busy entrance.
An expert notices that a red light and a spoken 'payment declined' are the only failure signals. They propose a text status with a clear heading and next action, verify controls can be reached and operated, and ask visitors using assistive technology to test the payment and recovery sequence. They do not infer success from the presence of two modalities alone.
Try a decision →03 / Decide
Guided decision
A kiosk gives a spoken direction in a noisy hall and also shows a color-coded arrow. Which first revision would you test?
Feedback on your choice
What could change the answer: If the kiosk is used outdoors in bright light, contrast and glare testing may change the visual treatment; if the direction contains private information, the audio path may need individual control.
This feedback helps you examine the decision; it does not grade your written reasoning.
Apply it somewhere new →04 / Apply elsewhere
Independent application
Fictional scenario
A voice-only smart speaker guides a person through pairing a home device.
Identify where a voice-only sequence fails for someone who misses a step or cannot hear it, and propose accessible alternatives without assuming a screen is available.
Make: A barrier and alternative map for the pairing journey, including a repeat and recovery path.
The learner identifies who is excluded, distinguishes the setting from personal ability, and provides an equivalent way to complete the essential task.
Lesson complete
You applied the method in a new context.
You studied the idea, tested a decision, and made an artifact for a new context. Keep the reasoning for your next UX question.
05 / Keep working