Managing Accessibility in an XML Instance

1
Managing Accessibility in an XML Instance

• A Proposal from
• the Internal Revenue Service presented to the
  Federal CIO XML Working Group

Department of the Treasury Internal Revenue
Service
David W. Heiser, Technical Advisor Tax Forms and
Publications Division April 2003
2
Problem Definition

• What is meant by inaccessibility a visual
  illustration (pun intended)
• What are the legislative mandates
• How to address with minimal burden on authors
• How to manage solution

3
A Graphical Black Hole
4
Legislative Mandates

• Section 508 of the Rehabilitation Amendments Act
  of 1998 requires government to provide access to
  information for persons with disabilities that is
  comparable to access to others
• The Americans with Disabilities Act prohibits
  discrimination and requires equal access to
  services for persons with disabilities
• The E-Government Act of 2002 requires agencies to
  make their web sites more efficient and usable
  using XML

5
IRS Perspective Some Issues

• Authoring process minimize complexity
• How do we move the process to the authoring side
  from post-production
• Maintenance of descriptions
• Research What standards exist, what
  nonproprietary solutions are available

6
What the Standards Revealed

• Research mostly on web pages little on dealing
  with accessibility in the source files.
• XML structure to support accessibility not
  specifically defined.
• Scalable Vector Graphics (SVG) some answers but
  dont specifically address IRS development,
  production, or web delivery needs. Still too new.
• MathML some solutions but requires plug-in and
  hard to use for non-math oriented authors.
• Proprietary solutions dont reach broadest
  audience (browser readers are expensive and
  proprietary).

7
Enlightenment

• National Braille Association recommendation from
  W3C website.
• An accessible graphic is one accompanied by a
  clearly written description for aural
  perception, not from a typical narrative style.
• Thus, for example, to mark up a flowchart, take
  the reader from decision to endpoint as you might
  in a conversation. If finished, provide an
  immediate exit point. Requires rewriting
  flowcharts to complete one path at a time.
  Minimal linking moves reader from path to path as
  necessary.

8
Summary of Accessibility Requirements

• Graphics
• Alt attribute on small or less busy graphics
• Description files for information-filled objects
• Tables
• Summary, title, or caption or combo
• Scoping with location (axis, header information)

9
Potential Issues

• Graphic descriptions too long for alt
• Description files dont provide structure for
  authors they want neat packages.
• Solution requires easy transformation for HTML
  display
• Some issues with multiple table models
• Simple portability -- no loose pieces to track

10
IRS Structure Solution

• Convert graphics to tables where possible
• Accessorize tables
• Summaries
• Header rows
• Scoping
• New descriptor container element a subset
  providing easy import into existing XML/SGML DTDs

11
IRS Solution (continued)

• Wrap graphics and their descriptions in container
  element (ltillustrationgt)
• New description element ltdescriptorgt to provide
  tagged organization
• ID matching of graphic, descriptor, and web page
  anchor
• Provide navigation (linking points, including
  exit points) for the text reader (e.g. end of
  graphic description)

12
DTD Subset

• lt!-- DESCRIPTOR
  --gt
• lt!ELEMENT descriptor (desc-title?, (desc-p
  desc-blst desc-nlst
• desc-slst table
  desc-hd)) gt
• lt!ATTLIST descriptor linkto IDREF
  REQUIRED gt
• lt!ELEMENT desc-p (PCDATA a
  desc-emph) gt
• lt!ELEMENT desc-blst (desc-hd?, desc-li)
  gt
• lt!ELEMENT desc-nlst (desc-hd?, desc-li)
  gt
• lt!ELEMENT desc-slst (desc-hd?, desc-li)
  gt
• lt!ELEMENT desc-hd (PCDATA)
  gt
• lt!ELEMENT desc-title (PCDATA desc-emph)
  gt
• lt!ELEMENT desc-li (PCDATA a
  desc-emph) gt
• lt!-- END of
  DESCRIPTOR --gt

13
Two table models

• DTD revised to include two table models
• CALS table for regular production, including
  print output
• HTML table model for descriptor subset
• Composition output can ignore descriptor table
  while XSL stylesheet can present same in separate
  browser window

14
HTML Table Illustration
15
Markup illustration with trickery

• Using the concept of tag templates to insert HTML
  table markup
• lttable summary"This is a test Table" border"1"gt
• ltcaptiongtCups of coffee consumed by each
  senatorlt/captiongt
• lttrgtltth scope"col"gtNamelt/thgt
• ltth scope"col"gtCupslt/thgt
• ltth abbr"Type" scope"col"gtType of
  Coffeelt/thgt
• ltth scope"col"gtSugar?lt/thgtlt/trgt
• lttrgtlttdgtT. Sextonlt/tdgtlttdgt10lt/tdgt
• lttdgtEspressolt/tdgtlttdgtNolt/tdgtlt/trgt
• lttrgtlttdgtJ. Dinnenlt/tdgtlttdgt5lt/tdgt
• lttdgtDecaflt/tdgtlttdgtYeslt/tdgt
• lt/trgt lt/tablegt

16
IRS Application Solution

• Customized authoring tool
• Built-in validation

17
Descriptor Management

• Tools include collection of descriptors
  throughout file and navigation.
• Author edits descriptor in separate window.

18
Next Steps

• Fine-tune multiple table model issues
• Contract to write and tag descriptor content
• Impress on authors need to own descriptor content
• CGI code to display descriptor in separate
  browser window

19
Some References

• Web Accessibility Initiative - http//www.w3c.org/
  WAI/
• GSA Section 508 Initiative -http//www.section508.
  gov/
• MathML Recommendation - http//www.w3.org/Math/
• Scalable Vector Graphics - http//www.w3.org/TR/SV
  G11/

20
Acknowledgements

• Joanne LaRose Plexus Scientific, Inc.
• Meribeth Miller Albina Delozier Management
  Systems Design, Inc.
• Nancy Odell, Brian Connolly, Deborah Durbin --
  Arbortext, Inc.
• IRS Alternative Media Center