A Principles-Based
Approach to Web
Accessibility
Jared Smith
http://webaim.org

Test Questions
1. True, False, or I don’t know
My web content is currently
accessible.

2. The five main categories of disabilities
affected by Internet accessibility
barriers are...

3. Web accessibility is easiest to implement
A. As the culminating step after user tests
B. As an integral part of the design process
C. By creating an alternative version
D. After receiving a complaint by a person
with a disability

4. Which of the following is cited most
regarding inaccessible web sites?
A. I wasn’t aware of the problem
B. Accessibility will hinder the look/feel/
functionality
C. I didn’t know how to make it accessible
D. We don’t have the budget to make it
accessible

5. True or False
Accessible web design benefits only
a small percentage of the
population.

Accessibility
“Development of information
systems flexible enough to
accommodate the needs of the
broadest range of users...
regardless of age or disability”
8.5% of the population has a
disability that affects computer use

The Evolution of Web
Accessibility Guidelines
• WCAG 1.0 (1999)
• Section 508 of the
Rehabilitation Act (2001)
• WCAG 2.0 (2008)

WCAG 1.0
• Finalized in 1999
• Checkpoint driven
• Priority 1, 2, and 3 (Level A, AA, and
AAA)
• Specific to HTML

Section 508
• Legalistic - easy to verify compliance
• Applies to federal government
• Very limited in scope. The de facto
standard.
• guidelines.
Many states have adopted the
• Currently being updated

WCAG 2.0
• Finalized December 2008
• Principles Based
• Technology Agnostic
• Maintains Levels (A, AA, and AAA)

Americans with
Disabilities Act
• Pre-dates the web
• “Places of public accommodation”
• Currentthe web to expand ADA to
include
proposal

Your site can be
compliant, yet
inaccessible

Your site can be
technically accessible, yet
functionally inaccessible

Web Accessibility
... it’s not rocket surgery!

... but don’t bite off more than you can chew.

P
O
U
R

P erceivable
O perable
U nderstandable
R obust

Ensure POUR content
across disability types
Vision - blind, low-vision, color-
blind
Deaf and Hard-of-hearing
Motor
Cognitive
Seizure

P erceivable
O perable
U nderstandable
R obust

Perceivable

Perceivable -
Auditory Disabilities
•Captions for video & live audio
• Text transcripts for all audio
content

Perceivable - Visual
Disabilities
• Web pages are linear
• Use meaningful links. Avoid “click here”.
• Alternative text for non-text elements
• Page is readable and functional at a minimum
of 2X zoom and 2X font size

Perceivable - Visual
Disabilities
• Associate text labels with form elements
• Associate data cells to row/column headers
• Sufficient contrast - http://webaim.org/
resources/contrastchecker/
• Ensure that meaning is not conveyed with
color alone

You’ve won the lottery! Press the GREEN
button to accept your prize and the RED
button to decline.

You’ve won the lottery! Press the GREEN
button to accept your prize and the RED
button to decline.

The green mushrooms listed here are
OK to eat. The red mushrooms will kill
you.
• Amanita
• Chanterelle
• Porcini
• Shitake
• Tylopilus
http://colorfilter.wickline.org/

The green mushrooms listed here are
OK to eat. The red mushrooms will kill
you.
• Amanita
• Chanterelle
• Porcini
• Shitake
• Tylopilus
http://colorfilter.wickline.org/

vs.
Vitally Important Text

P erceivable
O perable
U nderstandable
R obust

Operable

Who does this affect?
• Motor disabilities
• Fine motor control and use of a mouse
• Repetition and fatigue
• Control over timing or moving elements

Be careful with flashing/
strobing images
• More than 3 times in any one-second
period
• Size, brightness, and red threshold
• Annoying rule
• WARNING: This page can cause seizures
- fletchowns.net/what.html

Operable
• Ensuring keyboard accessibility
• Don’t remove focus indicators
• Ensure links are clearly distinguishable
• Logical reading/navigation order
• Consistent navigation elements

Operable
• Allow user to skip over repetitive and/
or lengthy lists of links
• Error-prevention and recovery
mechanisms
• Give user the control over time-
sensitive changes

Secret of Everlasting
Happiness

Secret of Everlasting
Happiness
Please finish reading this text
– it will give you the secret to
everlasting happiness. The secret
is simple, all you need to do is to stop
worrying about the key to everlasting
happiness and enjoy the moment.

Secret of Everlasting
Happiness
Sorry! Time’s up!
Better luck next time!

Separate content/functionality
from visual design

Web Developer Toolbar for Firefox

FAIL!

Can you have too much accessibility?

Direct users to content

P erceivable
O perable
U nderstandable
R obust

Understandable

Who does this affect?
• Cognitive disabilities
• Largest disability group. Larger than
all the others put together.
• Everyone!
• Because users vary greatly, we’ll focus
on generic recommendations

Understandable
• Be careful with movement and
other distracters
• Semantic organization (headings,
lists, etc.)
• Be consistent.
• Strive for brevity. Use the simplest
language possible.

Understandable
• Focus the user’s attention
• “Chunk” and/or simplify content
• Balance cognitive load vs.
funtionality

Understandable

Understandable

P erceivable
O perable
U nderstandable
R obust

Robust

Robust

Robust

Robust

Robust

P erceivable
O perable
U nderstandable
R obust

wave.webaim.org

Thank You!
Jared Smith
http://webaim.org
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