Transcript Web Accessibility 3.0 - University of Washington

Web Accessibility 3.0
Rick Ells
[email protected]
University of Washington
Seattle, Washington
Goal
We are in the business of helping people
climb mountains, figuratively speaking. Our
work should not put obstacles in their way.
What Are We Doing?
• Serving our clients
– All of the population of potential clients
• Supporting institutional goals and
purposes
– Serving all students well, including the
handicapped
• Delivering essential services through the
Web
– Continually improving service through
effective use of available technologies
Web Services
• Modern higher education relies on
the Web to do its business
• We have a diverse audience,
including people with handicaps
• Our audience is using a growing
variety of means to access our
services (PDAs, mobiles, laptops)
Device Independence
"A philosophical rule [that guided the
development of HTML] was that HTML
should convey the structure of a
hypertext document, but not details of
presentation. This was the only way to
get it to display reasonably on any of a
very wide variety of different screens and
sizes of paper."
Weaving the Web - The original design and
ultimate destiny of the World Wide Web by
its inventor,
Tim Berners-Lee
Accessibility
• Web technologies are designed to
support device independence
• Accessible design is a special case
of the the general goal of
maintaining device independence
• Device independent approaches are
essential to supporting the growing
range of devices connecting to Web
information and services
Making Progress
Down through the Web ages, we have
made progress in sustaining and
expanding device independence
• Slop Code Age
• Tables Age
• X-C/P Age
Will we be able to sustain progress as
we begin building Web
applications?
Slop Code Age
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No DOCTYPE statement
End tags optional
No validation
Non-standard elements
Heavy use of attributes for color,
font, alignment, etc.
• Heavy use of tables (and tables
within tables) for layout
Tables Age
• May have DOCTYPE statement
• End tags required, except for empty
elements
• Heavy use of attributes for color,
font, alignment, etc.
• Heavy use of tables (and tables
within tables) for layout
• Some validation against standards
Typical Tables Layout
Problems With Table Age
• Major code bloat
• Tables imposed sequence on
content
• Changing presentation required
extensive code modification
• Different presentations for different
devices impossible
X-C/P Age
• DOCTYPE statement always present,
preferably XHTML Strict
• Content is in XHTML
– Logical markup using element types
according to their semantic role
– Headings, paragraphs, lists and list items,
etc.
• Presentation, including layout, controlled
with CSS
• All code validated against standards
X-C/P
• XML foundation
• Separation of content and presentation
• Utilization of semantic logical elements
enables efficient presentation control with
CSS
• Alternative attributes supporting nonvisual adaptive technologies
– Alternative texts for non-text elements
– Labels bind title to form controls
X-C/P Accessibility
• Can be keyboard accessible
• Alternative stylesheets possible for
different devices
• Logical structure of elements to help
in semantic interpretation and
navigation
• Coherent sequence of content
• Page-by-page display
Web 2.0
• Strong interest in improving functionality
and usability of Web interfaces
• Standardization of XHTML, scripting, and
XML makes possible reliable dynamic
modification of page content between
page loads with most graphical browsers
– AJAX, ATLAS, Dojo, Bindows
– FLEX, Flash - add rich media content
AJAX
From: Ajax: A New Approach to Web Applications
AJAX Enhancements
Accessible Web 2.0?
• Most current adaptive technology for the
Web is page oriented
• Web AT often “scrapes” a copy of the
page on load and is not aware of
subsequent changes made in page
content
– Does not directly monitor the DOM
• How can a voice browser signal changes
on a page and direct user to what has
changed?
• Houston, we have a problem!
Accessible UIs Exist
• User Interfaces that work with AT
– Gnome Accessibility Toolkit, Microsoft Activite
Accessibility, Java Accessibility API
• Features
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Standardized roles for interface divisions
Standardized properties for elements
Focus management
Interaction model
Device navigation mappings
Semantics interpretation
Change notification
Progressive Enhancement
• Build a foundation of standards
based, semantic, validated,
accessible content and function
• Enhance with rich media
– Do it in a way that users can fall back
to the accessible foundation if the rich
media does not work for the AT
What is a Web App?
• If important content is being
manipulated between page loads,
you have a Web application
– Graphics
– Content
• Evaluate by 1194.21 and WCAG2
AT Problems
• Adaptive Technology is not ready
– Still page-by-page oriented
– Often not standards based
• AT is often developed by small
companies for small markets
– Do not have deep pockets or large developer
communities to share the load
• AT is often expensive
– Once acquired, users are often slow to
upgrade it
Implications for Higher Ed
• Move carefully on rich media
– Explore progressive enhancement
– Learn about Web applications
• Are Web applications really needed,
relative to our goals and values?
• Can progressive enhancement methods
meet our needs?
• How can we move forward in improving
usability and functionality of our apps in a
field still being defined?
Accessible Web Apps
Needed: A working contract between
the Web page and AT
– Notifying AT of changes and their
location
– Managing focus in a way that can be
followed by AT
– Standard roles for document parts
Work is underway in the W3C
Dynamic HTML Working Group on
these needs
Things Can Fly Apart
As Web apps are created,
accessibility could be diminished for
other reasons
• Losing semantics
• Narrow technical perspective (silo
thinking)
• Toolkit bias
• Vague direction from management
Losing Semantics
<div class="question">
<div class="question_content">
<label for="element_3">
<strong>How do you expect to apply the knowledge
and insights gained from this training?</strong>
</label>
</div>
<div class="p_question_input">
<textarea id="element_3" name="element_3" cols="80"
rows="5"></textarea>
</div>
</div>
Some developers simply create divs with presentation
properties, avoiding semantic elements. With only class or
id names, how can AT know the semantic role of a div?
Accessible Web 3.0
• Full utilization of XHTML/CSS for
Web page design
• Semantic ontologies
• Standard role naming
• Disciplined use of scripting methods
• Mature interoperative contracts
between Web applications and
clients
Other Thoughts
• We need a Gecko-like project to
create a standard Open Source
adaptive technology engine
• We need a better understanding of
non-graphical ways of interacting
with processes in an application
– Is page model appropriate? What
about a process semantic ontology?