PDF Accessibility – part 3 of 3 (reading text)

This blog is the third in a series that explores PDF accessibility. This installment describes how to implement PDFs using Adobe LiveCycle Designer so that form text is accessible to users of assistive technologies.

In this series:

PDF Accessibility – part 1 (introduction) – an introduction to accessibility standards and technologies
PDF Accessibility – part 2 (reading fields) – a step-by-step guide on making form fields accessible

WCAG 2.0 Guidelines

1.3.1	Info and Relationships: Information, structure and relationships conveyed through presentation can be programatically determined or are aviable in text
1.3.2	Meaningful Sequence: When the sequence in which content is presented affects its meaning, a correct reading sequence can be programatically determined
2.4.1	Bypass Blocks: A mechanism is available to bypass blocks of content that are repeated on multiple Web pages
2.4.5	Multiple Ways: More than one way is available to locate a Web page within a set of Web pages except where the Web Page is the result of, or a step in, a process
2.4.6	Headings and Labels: Headings and labels describe topic or purpose
2.4.10	Section Headings: Section headings are used to organize the content
3.2.3	Consistent Navigation: Navigational mechanisms that are repeated on multiple Web pages within a set of Web pages occur in the same relative order each time they are repeated, unless a change is initiated by the user

These guidelines are all about making it easier for assistive technology users to find text.

This is important due to the way that assistive technology users interact with a form. Unimpaired users can rapidly identify form text. They have the benefit of being able to scan a form by eye in any direction that they choose and rapidly absorb large amounts of text. Assistive technology users can access the same information, but at a slower pace. Mechanisms are required to present form structure so that assistive technology users can navigate directly to areas of interest.

Tags

You add structure to your PDF by tagging text. Similar to the table of contents in a document, tags are used by assistive technology to provide the user with a summary of a form’s content and the ability to quickly navigate to an area of interest without having to take the time to read the entire form.

To make your tags available to assistive technology, you have to check the ‘Generate Accessibility Information (Tags) for Acrobat’ in the ‘Form Properties’ dialog window.

Headings

Add structure to your PDF by tagging the headings. Set the ‘Role’ property to ‘Heading Level X’ for text objects in the accessibility pallet.

Headings can be tagged in a hierarchy up to 6 levels deep. Use the same rules that you would in a document – tag heading level 3’s under heading level 2’s etc. Heading tags can only be applied to an entire text object – you cannot tag part of the text.

When an assistive technology user runs the commands to navigate headings, they will be given the ability to quickly browse the form’s structure and navigate quickly to the area of interest. For instance, JAWS10 can display the dialog window below and will read all headings or only those at a specified level and the ability to ‘Move To Heading’.

Lists

Add structure to your PDF by tagging lists. This is appropriate for simple text lists. Do not tag nested lists or lists that contain fields.

Set the ‘Role’ property to ‘List’ and ‘List Item’ on subforms in the accessibility pallet. The ‘List’ subform should contain at least one ‘List Item’ subform, but not necessarily at the top level.

When an assistive technology user runs the commands to read lists, they will be given the ability to quickly navigate to any list in the form. For instance, JAWS10 can display the dialog window below and will read the content of each list. Each item in the dialog represents a ‘List’ with all its ‘List Items’. The screen reader reads any text that it can find within the tagged subforms.