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L. Guarino Reid and T.Cotton
Adobe Systems Incorporated
345 Park Avenue
San Jose, CA 95110
Kh. Eghtesadi and J. Denham
American Foundation for the Blind
11 Penn Plaza, Ste. 300
New York, New York 10001
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 the 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(tm) 6.0 and Adobe Reader(tm) 6.0 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(tm) 6.01 software.
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, the PDF file format has represented a challenge to blind and visually impaired people. Its 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(tm) 6.0 and Acrobat(tm) 6.0 Professional utilized directly by blind and visually impaired users from AWS.
Accessibility of Acrobat(tm) 6.0
An essential requirement for experiencing optimal accessibility with Adobe Acrobat(tm) or Adobe Reader(tm) is the use of Tagged PDF. Logical structure was introduced in PDF 1.3; Tagged PDF was introduced in PDF 1.4. 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 PDFs on the Web are not tagged. This may be for 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 more likely a user relying on assistive technology will find the untagged PDF file inaccessible.
Evaluation of Acrobat(tm) 6.0 Accessibility
Acrobat(tm) 6.0 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(tm) 6.0 by people with disabilities. AWS evaluated Adobe Reader(tm) 6.0 and Acrobat(tm) 6.0 Professional 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 users, a visually-impaired user, and an 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. Due to the widespread existence and complexity of untagged PDF, Adobe attempts to support them as well as Tagged PDF. AWS provided technical recommendations for improving Adobe Acrobat(tm) 6.0 and Adobe Reader(tm) 6.0 related to product compatibility with screen readers, enhancement of Help, and the labeling of icons/graphics. Recommendations for Acrobat(tm) 6.0 Professional focused on more complete "prompting" information, better compatibility with screen readers, and keyboard substitutions for mouse-driven features.
Accessibility Features of Adobe Acrobat(tm) 6.01
In the weeks following the evaluation, several accessibility enhancements were incorporated into the release of Acrobat(tm) 6.01. 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.
Acrobat(tm) 6.01 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(tm) 6.01 related to the screen reader are listed below.
Quick Accessibility Check -This command checks whether a file:
A file which passes the Quick Check may still have accessibility barriers. It may contain images with no alternate descriptions, for instance.
Document Mode vs. Page Mode - Document Mode allows the screen reader to access all content in the PDF file. The user can then use 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, and 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(tm) 6.01, 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 only process the text on a page. They will not recognize tables and will not include form fields.
While the Adobe Reader(tm) 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.
Acrobat(tm) 6.01 provides accessibility features for low-vision users, including:
Adobe's commitment to product accessibility was further crystallized by the evaluation conducted by AWS. Through a systematic process, project collaborators - evaluators, marketing, product engineers, assistive technology partners, and Adobe management - were provided the opportunity for education, collaboration, and resolution of key accessibility issues. The results provided for the quick recognition of high priority barriers and the development of realistic and economically-feasible solutions.
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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