PDFs

Introduction

The Portable Document Format (PDF) from Adobe Systems has only been in existence around 15 years; but in that time, it’s managed to become almost the format of choice. This is mainly because of its ease of transferral across all operating systems; and the fact that it retains the integrity of a document. This works particularly well when printing and drawing, as it’s essential to be able to retain a document’s format no matter whose computer it runs on.

However, there is some debate about whether PDF is suitable for an online environment, despite its popularity. Indeed, it is the belief of some in the Secondary Sight Collaboration Group that it is not. What is less in doubt, however, is its difficulties when it comes to access for all, particularly people who use screen magnifiers or readers.

The prime reason for this is that, unlike a format such as MS Word, PDF is not accessible by default. In this context, “accessible” means “readable” – literally. Microsoft Word, WordPerfect, ASCII text documents are physically readable (if not particularly usable) with a screen reader, even if no accessibility elements are included. This is not true of Early PDF documents, however, which are simply recognised as images by screen reading software and therefore provide no feedback to the user. Since Acrobat 5, Adobe has been working towards changing this, beginning with tags.

A tag is a small piece of text, hidden within a document, which acts as a structural marker for the screen reader. Ensuring that these tags are in place is a good start along the road to accessibility of a PDF document. Unless you’re very familiar with the acrobat programme, manually adding tags can be time-consuming and frustrating. However, this is definitely recommended over any of the automated processes within Acrobat. Playing Tag by Jonathan Whiting will give you an introduction to this process.

If you’re not comfortable working with Acrobat itself, it is recommended that you use Microsoft Word to write the original (source) file and then convert to PDF. Ensuring that your source file is accessible will go a long way towards ensuring that the resultant PDF is also accessible. Visit our section on MS Word for instruction in this.

Now that all your style elements are in place, you can begin the conversion process. It should be noted that following this process checking your document using Acrobat is vital in case any access tweaks are necessary.

Word 2003

There is no way to natively convert from any Office 2003 document to PDF. However, there is a plethora of free and/or low-cost converters available. One free converter which may be of use is called DoPDF

This is a small file which acts as a virtual printer. Just click “print” and select it in place of a physical printer *such as Brother, or Epson) and save your new document.

Alternatively, the free, Open Office programme will also write to PDF. You can find it at: http://www.openoffice.org.

Word 2007

Unlike 2003, Microsoft now offers a free Save As PDF add-in which will work reasonably well as long as all accessibility elements are in place in your source document.

Having downloaded the add-in, do the following.

Click the “office” button, or press alt-F, then F again to select “save as”.
Choose the PDF option from the drop-down menu.
Choose the “options” button or press alt-A
Check the box marked “create bookmarks using”
Ensure the radio button marked “headings” is selected
Check the box marked “document structure tags for accessibility”. This will tell the conversion tool to use your logically-ordered access elements as tags.
Click “okay” or press the enter key when ready.

Note: you will need to check the finished document within Acrobat to ensure the document is as you intended and make changes where necessary.

Remaining Accessibility Challenges

With each version of Acrobat, Adobe is increasing the ease with which its documents can be made accessible. Some concerns remain, however.

Readers with low vision cannot increase the font if they need to.
This is set to change with the release of Acrobat 9 Pro which will use a style sheet to allow the font size to be altered by the reader. However, not everyone has access to the very latest versions of software, so this issue may remain a challenge for some time to come.
PDF will not transfer direct to braille.
While it is sometimes possible to use Adobe reader to save a PDF document as a text file which can be transferred to a braille note taker, the result can be error-ridden and messy; particularly if the original file has contained a lot of graphical material. The only other way to get PDF to braille is via additional expensive software (probably costing as much as one of the market leading screen readers) which most of the students are not likely to own. Even then 100percent success is not guaranteed.
Too many variables.
Perhaps the most significant reason behind the recommendations which follow is that the reader/user has no guarantee as to how the document was authored, and therefore little guarantee of accessibility. Some documents are encrypted for security reasons, while others simply do not contain the necessary tags. A screen reader must try to guess where those tags should go and the result can range from acceptable to all but unreadable. Others simply arrive as scanned images which a screen reader will not recognise. If you follow the above instructions when creating your own documents in PDF, the likelihood that it will be accessible will be increased.

PDF To TXT

This little utility, developed by Jamal Mazrui, is the latest in a long line of tools which have endeavour to address some of these concerns. For instance, if you wish to encrypt a document and your reader knows the password, PDF To TXT will endeavour to unlock it. Similarly, if you present a blind student with a scanned image, PDF To TXT will try to perform Optical to Character Recognition (ocr) so that it can be recognised by screen reading software. Once again, however, an application like this cannot guarantee the accessibility of your PDF document and there is the rub.

This is analogous to attempting to retrofit a building to make it accessible for people with mobility impairments rather than building the access features in at the beginning. Depending upon the building, results can range from acceptable to disastrous.

Try out this utility at: http://EmpowermentZone.com/p2tsetup.exe

Recommendations

Think about the intended use for your document before saving to PDF. Do you intend to print it or will it be distributed online?
How important is that formatting? If it was originally composed using Microsoft Word, for example, will it work just as well in that format?
If you intend the document for both environments, it is worth taking the time and effort to make the PDF version as accessible as you can. If you cannot do so, keep your source document as an alternative format which you can give to your blind or vision impaired student.
For a wide range of resources and articles on accessible PDF, visit Karen McCall’s Accessible PDF Resources page. Karen is a user of adaptive technology and has been writing, training and consulting for a decade or more. The page has a comprehensive list of articles regarding PDF accessibility.

Summary

PDF, though extremely popular, may be far better suited to the printed environment than to an online one, and there are significant challenges when it comes to access for all. If you do nothing else, stop and ask yourself whether you really need to use PDF to distribute your document. If it’s largely text-based, chances are some other format will work just as well. If you really want to use PDF, please put the time and effort into making it as accessible as you can; and keep your work in an alternative format in case this is not possible or practicable.

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