ACCESSIBILITY OF ADOBE(tm) ACROBAT(tm) SOFTWARE FOR PEOPLE WITH
DISABILITIES

L. Guarino Reid and T.Cotton
Adobe Systems Incorporated

Kh. Eghtesadi and J. Denham
AccessWorld Solutions,
American Foundation for the Blind




Summary

Adobe's suite of Acrobat(tm) software products enables users to create,
format, and read Portable Document Format (PDF) files from a variety of
applications. PDF files are an industry standard for sharing
richly-formatted documents. More than 20 million documents are available
using this format on the Worldwide Web, with more than two million on
government web sites. Corporations and institutions, across industries,
compose and disseminate everything from user manuals to annual reports
to legal documents using the PDF file format.

To assure accessibility of Acrobat(tm) software for disabled users,
Adobe Systems Incorporated engaged AccessWorld Solutions (AWS), the
consulting arm of the American Foundation for the Blind. The purpose was
to evaluate the accessibility features of Acrobat 6.0(tm) and Adobe
Reader 6.0 (tm) software products and provide recommendations for making
PDF files more accessible to people with disabilities. This paper
summarizes the results of that evaluation and discusses how the results
contributed to improving the accessibility features of Acrobat 6.01(tm)
software.


Background

For individuals who cannot access standard printed documents, electronic
publishing offers individuals with disabilities the opportunity for
information access. Assistive technology provides the means for these
individuals to access information independently. Because of their
pervasiveness on the web and in the workplace, accessibility of PDF
files is critical to people with disabilities. However, since its
development, the PDF file format has represented a challenge to blind
and visually impaired people. This inaccessibility stemmed from the
inability of screen readers to completely and accurately read the PDF
document. This lack of complete access led to the belief that PDFs are
not usable by blind or visually impaired persons. During the past few
years, Adobe has attempted to remove accessibility barriers and present
a complete and readable PDF file to the screen reader. Improvements were
made at different levels, including collaborating closely with screen
reader manufacturers. In addition, Adobe conducted an accessibility
assessment of Adobe Reader 6.0(tm) and Acrobat 6.0 Professional(tm)
utilized directly by blind and visually impaired users from AWS.


Accessibility of Acrobat 6.0(tm)

An essential requirement for experiencing optimal accessibility with
Adobe Acrobat(tm) or Adobe Reader(tm) is the presence of a Tagged PDF
file. Logical structure was introduced in PDF 1.3 as part of Acrobat 4;
Tagged PDF was introduced in PDF 1.4, as part of Acrobat 5 in
2001.Tagged PDF files contain logical structure about the contents of
the file, similar to an HTML file. Tagging delineates the content's
reading order, identifies multi-column text, marks headings, indicates
table structure, permits the addition of alternate descriptions for
images and form fields, and provides information for reflowing a
document for low vision users. Tagged PDF is also essential for
accurately converting PDF to alternate formats (e.g., RTF, HTML, and
XML).

Most PDF's on the Web are not tagged. This is due to a number of
reasons: the PDF was created before Tagged PDF was developed, the PDF
was generated by an application which does not create Tagged PDF, or the
author did not know how to create Tagged PDF from the authoring
application. Untagged PDF files are not necessarily inaccessible.
Acrobat(tm) and the Adobe Reader (tm) attempt to deliver content to the
assistive technology whether or not the PDF file is tagged. The greater
the complexity of an untagged PDF file (e.g., multiple columns, presence
of graphics/tables, etc.), the greater the likelihood a user relying on
assistive technology will find the untagged PDF file to be inaccessible.



Evaluation of Acrobat 6.0(tm) Accessibility

Acrobat 6.0(tm) provides accessibility features such as a downloading
and installation capability, a quick accessibility check, extreme
magnification ratio, high contrast ratio color settings, and an embedded
Read Out function. On the Microsoft Windows Operating System, it
supports Microsoft Active Accessibility to expose document contents to
assistive technology.

The Accessibility Evaluation conducted by AWS was part of an Adobe
initiative to validate the accessibility of Acrobat 6.0(tm) by people
with disabilities. AWS evaluated Adobe Reader 6.0(tm) and Acrobat 6.0
Professional(tm) to identify major accessibility barriers. AWS
implemented an Accessibility Testing Procedure(c) to assess the user
interface and features of the software. This included using native
application files from Microsoft Office(tm) and real-life workflow
cases. Freedom Scientific's JAWS 4.51 was used as the screen reader. The
evaluation team included three blind accessibility experts, a
visually-impaired user, and a sighted accessibility expert. The process
was coordinated and observed by a number of Adobe technical and
marketing staff.

The evaluation confirmed that both products provide useful accessibility
features. However, due to the widespread existence and complexity of
untagged PDF, Adobe sought to maximize the power of its software. AWS
provided technical recommendations for improving Adobe Acrobat 6.0 (tm)
and Adobe Reader 6.0(tm) related to product compatibility with screen
readers, enhancement of Help, and the labeling of icons/graphics.
Recommendations for Acrobat 6.0 Professional(tm) focused on more
complete "prompting" information, better compatibility with screen
readers, and keyboard substitutions for mouse-driven features.


Accessibility Features of Adobe Acrobat 6.01(tm)

In the weeks following the evaluation, several accessibility
enhancements were incorporated into the release of Acrobat 6.01(tm).
Contributing to these improvements were the findings and recommendations
of AWS and the cooperation of the assistive technology providers at
Dolphin Oceanic, Ltd; Freedom Scientific Corporation; and GW Micro, Inc.
This section summarizes the resulting improvements.

Blind Users
Acrobat 6.01(tm) provides useful features for interfacing with the
screen reader, for checking and informing the user of accessibility
status, and for choosing the technique for calculating the reading order
in untagged files. The major accessibility features of Acrobat 6.01(tm)
related to the screen reader are listed below.

Quick Accessibility Check -This command checks whether a file:

- Has security settings that prohibits access by screen readers.

- Appears to be a scanned document. (No text is recognized in scanned
documents.)

- Contains no tagging to indicate the correct reading order.

- Reveals no accessibility barriers.

A file which passes the Quick Check may still have accessibility
barriers. It may contain images with no alternate descriptions, portions
of the content may be untagged, or the tagging may not reflect an
appropriate reading order.

? Document Mode vs. Page Mode - Document Mode allows the screen reader
to access all content in the PDF file. This provides the user with all
screen reader's functions to navigate the document. It ignores
artificial boundaries introduced by fitting the document onto physical
pages. Page Mode allows the screen reader to access only a single page
at a time. This limits the demands on the screen reader resources. A
single page loads more quickly than the entire document. However, the
user needs to use the Adobe(tm) Reader's navigation facilities instead
of the screen reader's for advancing. Reading Preferences lets the user
control whether documents should be delivered a page at a time, in Page
Mode. It also lets the user set a threshold for the largest document to
be presented in Document Mode.

? Reading Order - This preference controls which of the three algorithms
will analyze an untagged file. In Acrobat 6.01(tm), the default is "Use
reading order in raw print stream." This presents the words in the order
in which they are printed on the page by the authoring application. This
may or may not be the logical reading order for the page. The most
accurate results are produced by the recommended option "Infer reading
order from document", but this may be slow. The reading orders
"Left-to-right, top-to-bottom" and "Use reading order in raw print
stream" are faster than "Infer reading order from document", since they
attempt to process the text on a page. They will not recognize tables
and will not include form fields.

While the Adobe(tm) Reader is analyzing the structure of a page or
document, the user's screen reader is waiting silently and with no
feedback. For large documents, users should use a quicker option and use
the full inference only when they are not getting satisfactory results
from the simpler option.

Low-Vision Users
Acrobat 6.01(tm) provides accessibility features for low-vision users,
including:

64 times magnification ratio

High contrast ratio color settings with a variety of options

Read Out Loud feature utilizing native OS TTS engine

For Tagged PDF, a re-flowing function which arranges contents in a
single column that doesn't need horizontal scrolling at any
magnification



Concluding Remarks


Complete accessibility of Adobe(tm) software is a long-term goal to be
achieved by meticulously working with disabled people to address
accessibility issues. With future releases of Acrobat(tm) products,
additional accessibility features will be introduced and enhanced.


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