The use of PDF files on the web is actually quite a debated topic. Some argue that there is no place for PDF files, while others state that properly prepared PDF's are as accessible as HTML. Generally speaking though, their value lies somewhere in-between. The biggest plus to PDF’s is that the output displays exactly as the author intends regardless of what word processor software the end user has (Word, Word Perfect, etc).

But in order for a PDF to be truly accessible, it must meet two conditions:

1. It must be a well structured, correctly tagged, PDF.
2. The reader (yes, that’s the end user), must correctly configure their accessibility preferences in Adobe Reader.

When we talk about accessibility, most people think of it as referring to the accessibility for screen readers. But screen reader users are not the only people who should be considered when creating accessible PDF files. Not everyone with a disability is blind. Thus you need to consider the needs of individuals with motor disabilities, hearing disabilities, cognitive disabilities or low vision. For example…

Motor disabilities
Don't make your clickable elements too small, regardless of the fact that people have the option to zoom into the document. The smaller the link, the harder it will be for someone with limited fine muscle control to click on the link.

Hearing disabilities
Provide transcripts for audio elements. If you embed audio in your PDF files, you will be excluding both the deaf and the deaf-blind if you do not provide a transcript. Give them synchronized captions for video. Persons with hearing impairment need this if the video does not make sense when the sound is turned off.

Cognitive disabilities
Use simple language. It can be so hard to judge your own writing, so have others check it over for you and see what they think your main points are (and it doesn’t hurt that they can spell and grammar check for you anyway right?). The better you write, the better your message will be understood by everyone, not just those with cognitive disabilities.

Make the document accessible to screen readers. Not every person with cognitive disabilities use or benefit from hearing the content read to them. For the content to be read out loud, it must be accessible to screen readers.

Low vision
Contrast is key to these people. Ensure that any information conveyed with color is conveyed just as readable when color is not available.

Blindness and screen reader accessibility
Before version 5 of Arobat, PDF files were not accessible to screen readers in any useful way. Now it’s possible to expose the text in PDF files to screen readers, but much like Word and HTML, the PDF files must be created with accessibility in mind. The bad news is that it usually takes more work to make PDF files accessible than it does to make HTML files accessible. But it can be done!

Tagged Files

Creating accessible tagged PDF files will make PDF files accessible to standard screen readers which support tagged PDF (like JAWS and Window Eyes). It’s not always easy to make PDF files that are directly accessible to screen readers. Documents with complex layouts can be extremely difficult, if not impossible, to convert into an accessible PDF file, due to the fact that the content does not linearize correctly. It can also be very challenging to make documents with extensive charts or with embedded videos accessible.

PDF Tags are the text-only representation of the PDF file which is hidden inside the PDF document itslef, and is presented to screen readers instead of the original file. They exist for accessibility purposes only and have no visible effect on the PDF file.

HTML tags and PDF tags often use similar tag names and structures, but really are quite different. But if you are comfortable with HTML you will probably have an easier time creating and editing tagged PDF files.

If you have Acrobat 7 Pro, you can open it and practice features and techniques covered in the following article. An example of a tagged PDF is available at (external link) http://www.webaim.org/standards/508/508checklist.pdf

Tags Tab
Open a PDF in Acrobat Professional. The Tags tab lets you view, reorder, rename, modify, delete and create tags within this panel.

To view tags, select View > Navigation Tabs > Tags.

Expand <Tags> and <Sect>, by clicking on them, and a long list of tags is visible. The list can be navigated by mouse or keyboard. With a mouse, items can be expanded by clicking on the plus box next to the element. With the keyboard, use the left and right arrows. Navigation from element to element is possible using the up and down arrows.

After using the tags panel for a short time, you will notice a few of things:

• Tags sometimes have different names than in HTML
• There seem to be additional tags for spaces, and other little things that shouldn't need tags.
• Sometimes it’s hard to find which tag represents which element in the PDF.
• The tags don't seem as descriptive as in HTML.

Now you can see why it may be more clear why it is preferable to start with a correctly formatted Word Document. Imagine creating an HTML document without any access to the code, where every change requires several mouse clicks, and you get a taste for how frustrating it is to create a tagged PDF from a poorly formatted document.

Adding Tags
There is an option to automatically insert tags into an untagged PDF document
 
Choose Windows > Accessibility > Add Tags to Document to start this feature.

• Note that this operation can be time intensive, so be patient.

The User’s Side

The person using your documents must be running the FULL version (not standard) of Adobe Reader.

They should enable the Read Out Loud feature,
Select View > Read Out Loud

To change the default Read Out Loud attributes, choose Edit > Preferences > Reading from the list of categories on the left side of the window.

From here you can change several important attributes:

• Volume.
• Voice. The default is Microsoft Sam, which is is a very "robotic" voice, so any other voice is probably better.
• Pitch.
• Speed. This is one setting that screen reader users will probably want to increase significantly.
• Read form fields. This is an important setting. By default it is not selected, so unless you select this option, Read Out Loud will skip any form fields it encounters.
• To navigate from field to field, use Tab to move forward and Shift + Tab to move backward.
• The text entered in the field is not read as it is typed, but it is read when the user leaves the field.

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