Presentation on how usability and accessibility problems are related. Including people with disabilities in usability testing can reveal deeper insights into the kinds of problems users might encounter

1. Where usability
meets accessibility
Whitney Quesenbery, Center for Civic Design
Jayne Schurick, Knowbility

2. 2
Hi!
Whitney
User research, plain language, usability
Found accessibility through work on civic design
and elections.
Jayne
Usability
Found accessibility through Phillip Morris.

3. 3
Our starting point: user experience and
the user-centered design process
1. Understand
people and context
of use
2. Identify
requirements
3. Explore design
solutions
4. Evaluate
with users
Source: ISO 9241-210 (formerly ISO-13407)

4. 4
Accessibility and usability go hand in hand
Usability
The effectiveness,
efficiency and
satisfaction with
which a specified set of
users can achieve a
specified set of tasks in
a particular
environment.
– ISO 9241-11
Accessibility
The usability of a product,
service, environment or
facility by people with the
widest range of capabilities
– ISO 9241-20

5. 5
Accessibility error priorities
1. Critical
An absolute barrier to access
2. Serious
A barrier that could cause frustration to most and be a
barrier to some, causing a need for work-arounds
3. Moderate
A frustration that would not prevent someone from using
the site
4. Minor
A WCAG error that is unlikely to cause problems
- Glenda Sims, Deque
Source: 2103 Accessibility Summit: http://environmentsforhumans.com

6. 6
Usability problem priorities
1. Critical
A problem that will prevent some users from completing a
common task
2. Serious
A problem that will slow down some users and force them
to find work-arounds
3. Medium
A problem that will cause frustration but will not affect task
completion
4. Low
A quality or cosmetic problem, such as a spelling error,
that can damage the credibility of a site.
- David Travis, User Focus
Source: http://www.userfocus.co.uk/articles/prioritise.html

7. 7
Both evaluate priorities by impact on the user
How likely is it that this problem will stop someone from
being able to use the site?
Priority Label What it covers
Critical Barriers that stop someone from using a site or feature
successfully
Serious Problems that cause frustration, slow someone down,
or require work-arounds
Annoying
(moderate)
Things that are frustrating, but won't stop someone
from using the site
Noisy
(minor)
Minor issues that might not cause someone a problem,
but which damage credibility

8. 8
Examples of how usability and
accessibility problems interact
These examples are drawn from our experiences doing
usability testing. Although we show partial screens from
real site, these are simply typical problems, and not
unique to those sites.
In most cases, these companies are actively working on
both usability and accessibility, and some of the issues
described in this presentation have already been fixed.

9. 9
Coding errors turn a serious usability problem into a
critical accessibility problem
Usability problems (serious)
• Too many links (281 of them)]
• And 45 lists
• 98 Poor headings
• Overly complex information
Accessibility barriers (critical)
• Missing semantic coding:
• Headings
• In page navigation

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Noisy – easy to find - problems masked a critical one
Accessibility (noisy)
• Missing alt text
• Inconsistent heading coding
• Confusing labeling of
sections
But the real problem was
Accessibility (critical)
• No way to jump past the
infinite ribbon at the top of
the page

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All information and links are “accessible” but rely on
visual layout for meaning
Accessibility (serious)
• The overall site is
accessible
but
• The insert task links
rely on visual position
to tell you where the
task will be inserted.
Insert Task
Insert Task

12. 12
Long pages make information hard to find (even with
headers, without a table of contents
Really
really
long
page

Usability & Accessiblity
(Annoying to Serious)
• On a long page with a lot of
detail, users had trouble
finding specific information
Adding a well-designed "on this
page" menu helped everyone
decide whether this was the right
page

13. 13
The interface is harder than the test
Usability (serious)
Kids have to know how
use the tabs
Accessibility (critical)
Same problem, but worse
because the test question
is hidden
No heading
Follows long text

14. 14
Participants with disabilities add perspectives to a
usability problem
Usability &
accessibility(serious)
The general interface is both
usable and accessible, but the
language and terminology in the
content created serious and critical
problems for people who did not
know university terminology.

15. 15
Repeated and inconsistent page titles
make the IA incomprehensible
Usability (annoying)
Page titles repeat at different levels
Links and titles don't always match
Accessibility (serious)
Same problems have more impact
for screen reader or zoom text
users

16. 16
Look at real behavior, not just
coding requirements.
People with different interaction
styles add depth to usability.

17. 17
"The future is already
here...it's just not evenly
distributed."
– William Gibson

18. 18
Whitney Quesenbery
whitneyq@centerforcividesign.org
centerforcivicdesign.org
@whitneyq
Jayne Schurick
jschurick@knowbility.org
knowbility.org
A Web for Everyone
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