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The Australian Government's study into the Accessibility of the Portable Document Format for people with a disability


Accessibility, as defined by the International Standards Organization (ISO), is “the usability of a product, service, environment, or facility by people with the widest range of capabilities2. In discussing accessibility we cannot ignore the concept of usability. The standard definition is “the extent to which a product can be used to achieve specified goals with effectiveness, efficiency and satisfaction in a specified context of use3. The concept of web accessibility was propagated by the W3C with their publication of the initial WCAG version 1.0. The Australian Government has recently endorsed the updated web standard and requires all government websites to comply with WCAG 2.04.

Accessible websites provide all people with improved opportunity to access content to an equal or equivalent degree, as well as perceive, understand, navigate and interact with the web. However, web accessibility is contextual and many barriers exist to prohibit or limit a person’s ability to perceive, understand or operate web content. These might include visual, auditory, physical, speech, cognitive and/or neurological disabilities as well as situational contexts, the software platform chosen and the user’s level of skill.

While website accessibility is generally focused on improving information and services for people with a disability, it has broader application and benefits to all people. This Study deals with the PDF file type (ISO 32000) originally developed by Adobe. It is widely used for making documents available on web pages and for distributing documents in electronic format.

There is significant debate about whether PDF files are accessible to people with a disability. In the Australian context, the AHRC has maintained a strong position that the use of PDF files may present difficulties for people with a disability further recommending that alternatives be provided when PDF files are used.

In order to address the debate about whether PDF files are accessible to people with a disability, Vision Australia was commissioned by the Australian Government to undertake a study to determine the accessibility of PDF files for people with a disability, with particular reference to those who are blind or have low vision. The Study was conducted in three phases:

About WCAG 2.0

The release of WCAG 2.0 by the W3C on 11 December 2008 introduced the concept of ‘Accessibility Supported’ technology. WCAG 2.0 identifies techniques to create and manage web content (i.e. dynamic and static textual, visual, or audio electronic information) in ways that are more accessible to people with a disability. It promotes an approach of technology independence where the Guidelines can theoretically be applied to any technology, such as PDF, to determine its level of accessibility. A technology that has the capability to meet the guidelines and work with assistive technologies and the accessibility features of operating systems, browsers and other user agents is described as ‘Accessibility Supported’.

WCAG 2.0 stipulates that rather than just meeting specific technical criteria (e.g. noting how tables should be marked up in HTML), content should be Perceivable, Operable, Understandable and Robust. Under these four Principles, twelve Guidelines are organised which further clarify the purpose of each Principle. Each Guideline has a number of Success Criteria which provide a means to check conformance to that Guideline. Different web technologies (e.g. PDF, HTML, Java Script) will be able to demonstrate conformance to Success Criteria by applying ‘Sufficient Techniques’. As such, there will be multiple ways in which a website could claim WCAG 2.0 conformance.

WCAG 2.0 has been adopted by governments around the world. As a result, there is a need to determine whether it is possible to create PDF files that conform to the Guidelines.

In 2008, prior to the release of WCAG 2.0 as a Web Standard, the W3C published Reports on Accessibility Support for Ways of Using Various Web Technologies5. It included a report from Adobe to demonstrate how PDF files might address WCAG 2.0 Success Criteria. The report does not prove WCAG 2.0 conformance, nor suggest that the Portable Document Format is endorsed by the W3C as an ‘Accessibility Supported’ technology. The report developed by Adobe, Accessibility Support Documentation for PDF6, formed part of the Study and helped progress WCAG 2.0 to the next stage in the W3C web standard development process.

Accessibility Support Documentation for PDF and associated testing from Adobe did not include a complete collection of commonly-used assistive technologies used by people who are blind or have low vision, as identified in the second phase of this Study. As such, Vision Australia invited Adobe to conduct further tests with the most common assistive technologies used in Australia using the Adobe Test Suite methodology.

About the Portable Document Format

The Portable Document Format was created by Adobe Systems (Adobe) in 1993. In July 2008, PDF became an open standard, registered by the ISO as ISO/IEC 32000-1:2008 Document Management – Portable Document Format – Part 1 PDF 1.7. PDF files are widely used to publish and distribute information. For many, the attractiveness of using PDF is primarily in its ability to create a print-equivalent document that is readily available on most platforms. The software to view the files is also freely available on most platforms, hence its dominant market position.

It is possible to create PDF documents of different qualities. The application used to generate the PDF document and the process followed in creating it directly affects the accessibility of the resulting document. A PDF file can have a low, or no, level of accessibility (i.e. a scanned image) or a very high level (i.e. a fully-tagged PDF).

Accessibility considerations were first introduced for PDF files around 2001. Adobe worked with assistive technology vendors to improve compatibility between the assistive technologies and its Adobe Reader software. Assistive technologies rely on proper structural mark-up to provide the user with contextual information about a document. The ability of the PDF file to support this structural information, and of an assistive technology to interact with it, is the benchmark in determining if a PDF file is accessible.

Since Adobe Reader version 4.05, Adobe has introduced improved accessibility support and a number of accessibility features into Adobe Reader. These include: a text-to-speech document reader; presentation settings to allow the user to customise the appearance of the document to suit their preferences; and a utility to support assistive technology users by inferring the document structure for a PDF file where this has not been provided by the document author.

In their Accessibility Guide: PDF Accessibility Overview (2008)7, Adobe offers a comprehensive list of characteristics, which in their view, must be present in a PDF file for it to be optimised for accessibility. These include:

The PDF Universal Access Committee (PDF/UA) is developing an ISO specification for accessible PDF files. The standard will establish, independently of Adobe, a set of guidelines for creating accessible PDF files so conforming files will be more accessible and usable to all, including people with a disability. The PDF/UA documentation is currently in the committee draft stage. A full ISO standard is expected in 2011.

While a number of projects and organisations are involved in exploring the question of PDF accessibility around the world, there is no agreed definition on what constitutes an accessible PDF that can be applied at this time, other than those offered by Adobe or WCAG 2.0.

The legislative context in Australia

Access to information is one of the many aspects covered by the DDA. To help people in the community understand how the DDA applies to web content, the AHRC provide Advisory Notes. Through the Advisory Notes, the AHRC communicates a strong position about the difficulties that exist for people with a disability using PDF files. The Commission notes “that organisations who distribute content only in PDF format, and who do not also make this content available in another format such as RTF, HTML, or plain text, are liable for complaints under the DDA”. The Australian Government’s policy position has supported the AHRC.

The importance of ensuring that information is accessible to everyone in the community has been strengthened through Australia’s ratification of the United Nations Convention on the Rights of Persons with Disabilities (UNCRPD ) on 17 July 20088. The Convention includes articles that specifically relate to accessibility of information:

“(Article 9) ... requires countries to identify and eliminate obstacles and barriers and ensure that persons with disabilities can access their environment, transportation, public facilities and services, and information and communications technologies.

(Article 21) ... to promote access to information by providing information intended for the general public in accessible formats and technologies, by facilitating the use of braille, sign language (Auslan) and other forms of communication and by encouraging the media and Internet providers to make on-line information available in accessible formats.”

The endorsement of WCAG 2.0 for all Australian Government websites provides further evidence of the Australian Government’s commitment to more open and accessible information and services, especially for people with a disability.

As part of the endorsement of WCAG 2.0 and its proposed implementation across all government websites, clear guidance is required to assist web developers in understanding the implications that various web technologies have for people with a disability. Because of its widespread use, establishing the accessibility of PDF files and the impact of their use for people with a disability is tightly linked to the adoption of WCAG 2.0 in Australia, as is the ratification of the UNCRPD.

Computer use by people with a disability

In 2003, the ABS Survey of Disability, Ageing and Carers identified that one in five people in Australia (3,958,300 or 20.0%9) reported having a disability. This data only captures people who report that they have a disability. Many people do not consider their impairment to be a disability and do not report that they are disabled, so the figure may be higher. Additionally, it is widely understood that the number of people with a disability is increasing due to the ageing population. Information and services are becoming increasingly available online and the use of computers and the internet is growing at a rapid rate in the community – between 1998 and 2008-09, household access to the internet in Australia more than quadrupled from 16% to 72%. However, computer interaction can be severely hindered for people with a disability.

During the online consultation, a submission provided by Mireia Ribera Turró, Professor at Universitat de Barcelona Department of Library and Information Science detailed the types of disabilities that have direct effects on digital reading and associated activities. People with a disability often rely on various ‘adaptive strategies’ to improve interaction with computers. Some of these adjustments are relatively straightforward and available as part of their computer while others involve the use of an assistive technology – specialised hardware or software that extends the functionality of the computer to support the individual’s interaction method. It is important that web content creators have an understanding of these issues and so they have been included here.

There are three main groups of print disabilities that also affect the comprehension of graphics:

It is also important to understand how some of these assistive technologies work in principle.

Determining how each of these adaptive strategies applies to PDF files is essential in understanding the experiences of people with a disability and the discrimination implications that may exist. Because of the nature of their adaptive strategies, people who are blind or have low vision are considered to experience the most significant problems when accessing PDF files. This group rely on assistive technologies such as screen readers that interact with the elements and structure of the PDF file. Hence the technical ability of their chosen assistive technology in recognising those structures, coupled with the way the information is actually presented in the PDF file itself, is fundamental to their success.

For this reason, phase one and phase two of the Study focused on the experiences of people who are blind or have low vision. Phase three (user evaluations) included representation from all disability groups.

It is worth noting that the 2004 Clear Insight report11 identified that 480,000 Australians who reported having a disability were recorded as being vision impaired in both eyes, and over 50,000 of these people were blind. The report’s projections indicated that, due to an ageing population, blindness is set to increase by 73% over the next two decades.


  1. International Standards Organization, 2008, ISO/TS 16071:2003 - Ergonomics of human-system interaction – Guidance on accessibility for human-computer interfaces, viewed 5 April 2010, External Site
  2. International Standards Organization, 2008, ISO 9241-11:1998 -Ergonomic requirements for office work with visual display terminals (VDTs) — Part 11: Guidance on usability, viewed 6 April 2010, External Site
  3. Australian Government Information Management Office, 2010, Web Accessibility National Transition Strategy, viewed 1 July 2010, index.html
  4. World Wide Web Consortium, 2008, Reports on Accessibility Support for Ways of Using Various Web Technologies, viewed 23 April 2010, accessibility_support External Site
  5. Adobe Systems Incorporated, 2008, Accessibility Support Documentation for PDF, on W3C web page, viewed 23 April 2010, support_statement External Site
  6. Adobe Systems Incorporated, 2008, Adobe® Acrobat® 9 Pro Accessibility Guide: PDF Accessibility Overview, viewed October 2009, External Site
  7. United Nations, 2006, Convention on the Rights of Persons with Disabilities, viewed 30 April 2010, External Site
  8. Australian Bureau of Statistics, 2003, 4430.0 - Disability, Ageing and Carers: Summary of Findings, 2003, viewed October 2009, External Site
  9. Turro, M. R., 2008, Are PDF documents accessible?, Vol.27, no. 3, pp.25-43, Information Technology and Libraries, viewed October 2009..
  10. Eye Research Australia, 2004, Clear Insight: The Economic Impact and Cost of Vision Loss in Australia, report prepared by Access Economics Pty Limited, Melbourne, 2004


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Last Modified: 25 November, 2010