chapter 1
Accessibility 101
A short primer on what disability is, what accessibility means, and why building for the edges makes things better for everyone in the middle.
What is accessibility?
Accessibility (often shortened to a11y — eleven letters between the A and Y) means designing things so people with disabilities can use them. That includes physical spaces, hardware, software, language, and culture.
Around 1 in 4 adults in the U.S. lives with a disability. That number grows once you include temporary injuries (a sprained wrist), situational limits (bright sun, holding a baby), and aging. Accessibility isn't a niche feature — it's how good design works.
Two ways to think about disability
medical model
The person is the problem.
"Their body or mind is broken — fix or cure them so they fit the world."
social model
The environment is the problem.
"There's nothing wrong with the person — the world was built without them in mind. Change the world."
The disability community largely embraces the social model. As a hacker, this is your superpower: most barriers are made of design choices, and design choices can be unmade.
A wide community
You'll meet attendees and partners with lived experience across many communities:
Many disabilities are invisible. Don't assume from looks alone.
Permanent · temporary · situational
Microsoft's Inclusive Design team frames disability as a mismatch between people and their environment — and the mismatch shows up everywhere:
One arm
Permanent: limb difference · Temporary: broken arm · Situational: holding a baby
Can't hear
Permanent: Deaf · Temporary: ear infection · Situational: loud bar
Can't see screen
Permanent: blind · Temporary: eye dilated · Situational: glare at noon
Build for the permanent case and everyone else gets a smoother experience too. (That's the curb-cut effect: ramps cut for wheelchair users help strollers, suitcases, and delivery carts.)