What is accessibility?
Broad definition
- an approach to web design that aims for maximal inclusion - of people and user agents
The concept of the web is of universal readership. If you publish a document on the web, it is important that anyone who has access to it can read it and link to it.
Tim Berners-Lee (inventor of the web)
Definition in common use
- the ability for people with disabilities to access web content
The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect.
Tim Berners-Lee
Legal requirements for accessibility
Policies and legislation exist throughout the world
- Many countries now have legislation or policies requiring web site accessibility
- In Australia, Section 24 of the Disability Discrimination Act 1992 (DDA)
states:
24 Goods, services and facilities
(1) It is unlawful for a person who, whether for payment or not, provides goods or services, or makes facilities available, to discriminate against another person on the ground of the other person's disability or a disability of any of that other person's associates:
(a) by refusing to provide the other person with those goods or services or to make those facilities available to the other person; or
(b) in the terms or conditions on which the first-mentioned person provides the other person with those goods or services or makes those facilities available to the other person; or
(c) in the manner in which the first-mentioned person provides the other person with those goods or services or makes those facilities available to the other person.(2) This section does not render it unlawful to discriminate against a person on the ground of the person's disability if the provision of the goods or services, or making facilities available, would impose unjustifiable hardship on the person who provides the goods or services or makes the facilities available.
How the Australian legislation works
- DDA does not specify standards for accessibility (Section 508 legislation in the US does)
- Law is complaints-based
- Human Rights and Equal Opportunity Commission (HREOC) have power to make "Advisory Notes" or guidelines related to the DDA.
- Advisory Notes:
- aim to assist organisations meet their legal obligations
- not directly legally binding
- have been used as a yardstick to determine whether complaints are valid (in Maguire v SOCOG)
- recommend the use of W3C's Web Content Accessibility Guidelines 1.0 as best means to ensure obligations are met
References
- Disability Discrimination Act - Section 24
- World Wide Web Access: Disability Discrimination Act Advisory Notes
- Web Content Accessibility Guidelines 1.0
- Web Content Accessibility Guidelines 2.0 - Working Draft
- W3C: Policies relating to Web accessibility
- Decision in the case Bruce Lindsay Maguire v Sydney Organising Committee for the Olympic Games
- Olympic Failure: a case for making the Web accessible
What is PDF?
- PDF stands for "Portable Document Format"
- an electronic format that preserves a document's layout, fonts, links, images, etc.
PDF is widely used on the web
Reasons why PDF is so popular
- it is very easy to convert word processor and other formatted documents to PDF
- PDF reader is free
- PDF reader is available for many operating system platforms (Windows, Mac, Unix, etc.)
- has appealing features
- files can be password protected
- printing can be disabled (note: users can capture screens and then print)
- copying and extracting text can be disabled (note: determined users can still print and scan or capture, print, and scan)
Accessibility enhancements to PDF
- Acrobat 5 includes a number of accessibility features
- read PDF files with screenreaders - though the creation of "tagged" PDF files
- view documents in high contrast mode
- zoom in on text and reflow to fit any size view
- keyboard navigation support
- There are a variety of ways of making tagged PDF files
- converting from another format to tagged PDF using Acrobat 5
- converting existing PDF files to tagged PDF using the Make Accessible plug-in
- scanning documents and converting to tagged PDF using Adobe Capture 3.0 and Tag Adobe PDF agent
Acknowledged limitations of converting earlier PDFs to tagged PDF
- Macromedia acknowledge the following limitations
of the Make Accessible plug-in
- Font Encodings: The MakeAccessible Plug-In maps fonts used in the document to a Unicode value. In some cases, a font encoding used within a PDF document does not contain enough information for the MakeAccessible Plug-In to map to a Unicode equivalent.
- Table Recognition: The MakeAccessible Plug-In supports simple table recognition. A simple table would be a table that includes a single line rule around each cell of the table. Tables that do not include complete rules may not be recognized as table content.
- Complex Graphic Recognition: Documents that contain complex graphics (especially vector based graphics) could take a long time to process.
- Complex Regions: Documents such as magazines, marketing collateral, and newspapers contain complex layout. In some instances, the MakeAccessible Plug-In will not be able to ascertain the appropriate logical read order of a complex layout.
- Layer Order: Layers of objects within a complex PDF may be rearranged in a different stacking order, resulting in a tagged Adobe PDF that does not look identical to the original PDF.
References
Making tagged PDF files takes time and skill
- Macromedia are moving in the right direction in making PDF accessible
- however, making tagged PDF files is not easy
- the following example shows what might be involved when converting a MS Word document to tagged PDF
Step 1: The right tools must be used
- check whether original document was created using Word 2000 or later
- if created in an earlier version, open and resave in Word 2000 or later
- conversion must be done using Acrobat 5 which produces "tagged PDF" files
- "tagged PDF" files provide information about the logical structure and proper reading order of the document
- Acrobat 4 provided limited information about the structure of a document
Step 2: Structural formatting must be used
- check whether word styles have been used to indicate titles, headings and sub-headings
- check that word style have been used consistently
- re-style document as required
Step 3: Styles and page elements must be used correctly
Step 3.1 Paragraphs
- make sure the "Enter" key hasn't been used to add spaces between paragraphs
- each empty paragraph becomes an element in your PDF document
- paragraph spacing attributes should be manipulated create appropriate spacing between paragraphs
- remove empty paragraphs as required
Step 3.2 Columns
- make sure column formatting, rather than tabs, was used to create columns
- otherwise reading order will not be correct
- screen reader will read straight across two columns rather than down one and then down the other
Step 3.3 Tables
- check that tables are properly formatted, using "Insert table" or "Draw table" rather than tabs
- can Word structurally format complex tables? Will the structure be preserved/added in the conversion?
Step 4: Graphical elements must be given a text equivalent
Step 4.1 Images
- check all images to ensure that equivalent text alternatives are provided
Step 4.2 Illustrations
- group related elements together, as required
- check that the grouped elements have a text equivalent
Step 5: The correct conversion settings must be used
- Open your document in Word 2000
- Select Acrobat > Change Conversion Settings
- Select the "Office" tab
- Ensure "Page Labels" is turned off
- Ensure "Embed Tags in PDF" is turned on
- Select the "Bookmarks" tab and check all the elements that you want converted to bookmarks. Select only those that the disabled user is likely to find useful for navigation (e.g headings) and click OK.
Step 6: Run the conversion and save the PDF document
- Select Acrobat > Convert to Adobe PDF
- Enter an appropriate filename and click OK
Step 7: Check the resulting PDF document for successful conversion
- Open the new tagged PDF document in Acrobat
- Select Tools > Accessibility checker
- Select the options shown below and click OK
- Note the results provided by the Accessibility checker
Step 8: Open the tags palette to make corrections
- With the document still open in Acrobat, select Windows > Tags to display the Tags palette
- Drag the Tags palette tab to the let of the screen to dock it with the other palettes
- Select the Tags palette tab
- Expand the Tags root and tags beneath it until you locate the elements that require correction
Step 9: Make corrections
- Select an element tag that requires correction
- It's a good idea to "Turn on associated content highlighting" from the Tags palette menu
- With this on, you can see the part of the document that corresponds to the element tag you have selected
- Right-click on the element tag and select "Element Properties"
- Edit the element as required
Step 10: Test with a screenreader
- Not everyone will have access to either JAWS or Window Eyes
- If you do, checking the document with a screenreader is the best way to ensure that it is readable
- Check the following:
- is the read order correct?
- is tabular data read properly?
- are form field names associated with input areas?
- are text alternatives read, and do they make sense?
References
- Adobe 5.0 accessibility FAQ
- How to create accessible Adobe PDF files
- Advanced techniques for creating accessible Adobe PDF files (pdf format, 386Kb)
PDF accessibility - the fine print
PDF is only accessible when ALL of the following conditions are met
- original document was created in an application that permits the creation
of "tagged
Adobe PDF"
(e.g. MS Office 2000+ or Pagemaker 7+ on Windows platform only) - original document was created with:
- properly defined and styled structure
(header styles, formatted columns, tables and lists) - text descriptions of images
- low security settings (see screenshot below)
- properly defined and styled structure
- conversion was done using Acrobat 5 with correct conversion setup
- converted document has been checked to ensure conversion process was successful
- blind users have appropriate screen reading technology
- A Microsoft Active Accessibility [MSAA]-compliant reader (JAWS or Window Eyes)
- Acrobat reader with accessibility functions and the necessary patch
- screen reader is running on Windows platform
Therefore PDF has limited accessibility
- not all original documents are created using the right tools (wrong application, wrong platform
- not all original documents will have been properly authored
- not all blind users have the appropriate screen reading software
- not all blind users use a Windows-based machine
- you can't "protect" intellectual property and create a tagged PDF file
Appropriate use of PDF on the web
- As a result of the limited set of conditions in which PDF might be accessible, HREOC issued
the following statement (in August 2002)
The Commission's view is 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
Need to have an information management strategy for the web
- Identify the most critical/important content on your web site
- Make sure this is accessible
- Ensure there is a request/contact service for less important content that is not accessible
- All newly-created content should be accessible HTML
- Where this cannot be achieved, ensure the content is provided in multiple formats
- Use PDF only when an accessible alternative is also provided (in HTML, RTF or TXT format)
- PDF is best used to provide printable versions of web content
References
Inappropriate use of PDF on the web
- A lot of web content is published only in PDF format
- Google's "View as HTML" version of PDF documents is useful, but content is not always fully accessible
Google "View as HTML" examples
- Compare the View as HTML version of this extract from the document (first screenshot below) with the extract taken from the PDF version of the file (second screenshot below)
- The read order of the document may be adversely affected with the result that a screenreader may not correctly associate the labels P and Q with the appropriate explanatory text.
- Compare the View as HTML version of this extract from the document (first screenshot below) with the extract taken from the PDF version of the file (second screenshot below)
- The column layout may result in some screenreaders reading straight across the screen (IBM's Home Page Reader did handle the columns properly)
- Some characters did not convert properly and make the text difficult to understand
- The text has been prepared to fit very tightly around an image and so many words are broken with a hyphen and would read awkwardly in a screenreader
Monash examples
- The following are screenshots as captured with The Wave
- The Wave highlights any links on a page that are to PDF documents
- The Wave marks these links with the PDF icon and the text "Is it in tagged PDF format or is an HTML alternative provided?" - note: the "or" relates to US legal requirements. HREOC cautions Australian organisations to provide an alternative accessible format even if the PDF file is tagged PDF
1. Monash Annual Report
- Note: it is not the sight-impaired who need to visit the Adobe accessibility pages, but the author of this page!
2. IT Strategic Plan
3. Student employment news
4. Student accommodation policies
Other university examples
1. Central Queensland University - Student information page
2. James Cook University - Student accommodation page
3. Edith Cowan University - home page
