Presented at a Leadership Institute webinar for the Montana Arts Council in May 2012. Primarily a talk discussing the concepts behind the WCAG 2.0 guiding principles.
Based on the December presentation for the Montana web programmers meetup, but modified for the audience.
2. Who am I?
- A web designer and programmer
- An advocate for web accessibility
- A writer on practical accessibility
- Read more at http://www.joedolson.com
3. What am I going to talk about?
1) Overview of web accessibility principles
2) Examples of testing methods (with and without tools)
3) Tools and resources for further work.
5. Fundamentals
- Techniques:
- Technology specific
- Rapidly changing as technology shifts
- Principles:
- Technology independent
- Change as research learns more about human
cognition
8. Perceivable
- your product can be perceived regardless of disability.
People who cannot use one or more of their senses can still
obtain the information on your web site.
9. Perceivability Red Flags:
- Is information contained in an image? A sound file? A
video?
- Does the information require specific knowledge to
interpret, such as awareness of position on the page or color?
- Does the document use HTML headings?
- Does the document's contrast meet minimum
specifications?
10.
11. Perceivability Requires Imagination
- Imagine the MANY possible ways to access your site:
- If the user cannot hear sounds (no speakers, Deaf or
Hard of Hearing)
- If the user cannot see images (non-image rendering
browser, blind or sight-impaired)
- If the user is not using the site as you laid it out (re-
drawn by a mobile browser or linearized by a screen reader)
12. Operable
- your product can be operated regardless of disability.
People who cannot use one or more of their senses can still
perform actions such as navigation, purchasing, or
communicating at your web site.
13. Operability Red Flags
- Can you easily distinguish link text from other text on the
site?
- When navigating without a mouse, can you tell where
you are in the site? Is the navigation order logical?
- On a form, can you navigate the form without a mouse?
Do you have to use fine motor skills to successfully select
options?
- Do pages have unique titles?
- Are links clearly labeled? (e.g. not “Read more” or “Click
here”)
14. Both menus have the
“Express Free” option
selected. The left is
using a keyboard.
15. Operability is Complicated
When it comes to forms and complex applications such as
video players, operability is very difficult to test thoroughly
without specialized knowledge and tools. However, the
keyboard test is a good start for any issue.
16. Understandable
The Information on and operation of the site must be
understandable. Users must be able to understand the
information as well as the operation of the user interface.
17. Understandability Red Flags
- Are interface methods consistent with expectations?
Links should be underlined; other text not.
- Is navigation consistent from one page to the next?
- Are functions identified consistently? (“Search” on one
page and “Find” on another)
- In a form, is it clear what information is needed and how
to enter it? (Dates, phone numbers, and other formatted data
in particular.)
- Is the language of the document specified?
18. Robust
- Your site is built according to standards.
A site is robust if it will be maximally usable on a wide range of
browsers or devices; building with W3C HTML standards helps
ensure that it will be usable on future devices or browsers.
Validating your site with the W3C's validator tool is the
primary test for this: http://validator.w3.org
21. Testing doesn't always need special tools
- Understanding how people with disabilities use a site
- Learning how to see potential problems
- Applying the principles of accessibility
22. Think like assistive technology
- Imagining you are blind isn't sufficient; you also have to
think like a machine
- You have to understand what information is available to
the computer.
This form of testing is only an overview: it can't detect every
problem. It can forestall endemic issues, however.
23. The Blind Experience
- Is keyboard dependent.
- Uses complex keyboard commands
- Gets information about visual objects from related text
Can links be visited via keyboard? Form fields? Submit
buttons? Are form responses announced when a form is
submitted? Has the web site defined keyboard controls which
may conflict with the assistive technology? Do images and
media files have text equivalents?
24. Low vision or partial sight.
- Use OS tools or assistive technology with screen
magnification
- May adjust browser settings to increase font size
- May use alternate contrast schemes
- May have narrow field of vision
Is all text visible when the font size is enlarged? Are line
lengths too long using screen magnifiers? Is contrast
sufficient for text to be legible with poor light perception or
color blindness? Do instructions depend on color
identification for success?
25. Reduced motor skills.
- May use a mouse, but have difficulty controlling it with
precision.
- May be keyboard dependent.
- May use special pointing devices such as a mouth stick,
head wand, or eye tracker.
Are clickable areas large enough to activate using less refined
pointing devices such as a mouth stick or head wand? Is
keyboard focus visible, so keyboard dependent users can tell
what they are currently activating?
26. Cognitive Limitations.
- May need extra time to complete time-based tasks.
- May become confused if navigation or layout of site
changes significantly from page to page
- May need orientation tools to return to previous pages
- May be highly distracted by motion or sound
Concerns relating to learning disabilities range broadly across
issues with recall, comprehension, reading skill, attention, and
spatial cognition. Use of contrast, color coordination of
related items, choice of fonts, and simplification of written
text are among the rich variety of strategies for supporting
these issues.
28. Overview of testing.
The best testing is to put a group of assistive tech users in
front of your site, and set them tasks to accomplish. This is,
obviously, beyond the means of most developers and clients.
The compromise is threefold:
- Limit use of newer, less-tested technologies.
- Research new features thoroughly.
- Do as much testing as you can.
29. General purpose tools (free!).
- Firefox Accessibility Toolbar: http://bit.ly/firefox-toolbar
- Internet Explorer Accessibility Toolbar:
http://bit.ly/ie-toolbar
- WebAIM's WAVE tester: http://wave.webaim.org
- Windows 'Ease of Access': http://bit.ly/ease-of-access
- MacOS Accessibility: http://bit.ly/mac-access
37. Finding more information.
- WCAG Recommended Techniques: highly technical, though
simpler than the WCAG itself.
http://www.w3.org/TR/WCAG-TECHS/
- WebAIM: Simplified summaries, recommendations.
Extensive documentation on almost every accessibility topic:
http://webaim.org
- University of Minnesota, Duluth Web Design References:
Extensive curated catalog of accessibility articles on the web:
http://bit.ly/t3tPZC