Can PDF files be made accessible to people with visual impairment or who need assistive technology to use the internet?
A college of mine recently asked this question, above, and thought I would post my thoughts.
To use PDF or Microsoft Word files with assistive technology effectively content creators must create files that have this in mind. This essentially means that the design needs to consider the user and that the document should contain good structured and tagging. To do this each element that makes up a document needs a definition – so define text that is a top-level heading (the title of a book) separately from a sub heading and from body text using styles – tag images to give an alternative text description that indicates an image in a non visual environment.
Design and publishing tools such as Adobe InDesign and Microsoft Word do deliver help in creating well structure documents, using style sheets and tagging tools, some of which is automatic. However to achieve a high quality solution this task needs considering fully as part of the process of creating the document file.
It is perfectly possible to take a PDF and complete all the tasks required to create an accessible file using Adobe Acrobat Professional or the newer version Acrobat X (please note this refers to the full editing versions of this software and not the free reader only options available). However, creating fully accessible documents using Adobe InDesign and Acrobat or Microsoft Word is still a pretty complex task. To be cost-effective it really needs building into the process from an early stage via templates in my opinion. The latest version of Adobe InDesign CS5.5 is reducing the need to complete tasks separately in Acrobat by allowing preparation in the source InDesign file. These preparations transfer into in the PDF without issue, something which is a vast improvement on older versions. The new features of Adobe CS5.5 are explained in two great videos found at the Adobe TV learning resource.
My knowledge of Microsoft Word is not as strong but my understanding is that while Word generally produces well structured content, achieved by using the built-in style sheets, there is still a need address images and make adjustments to make sure the PDF is of a high standard. WebAIM provides this useful introduction.
In the past Adobe restricted some of the more complex tasks to Adobe Acrobat and these were a pretty manual task. This is improving with much more automation available. Acrobat X’s improved scripting and accessibility features mean that much of this could be managed using a simple workflow to help.
In addition Acrobat Reader actually delivers many accessibility features which people do not realise. For example the accessibility preference settings in Acrobat allow the display of coloured text in black on white no matter what colour the text or background are. This effectively means that even documents with poor colour contrast are accessible (although I would always promote this being considered as part of the general design). It also allows for text to reflow allowing the increase of text size without the need to scroll horizontally (with good tagging applied). Acrobat also includes a read out loud function which will correctly read a PDF if tagged properly, meaning that alternative screen reader software is not required. This is I believe essentially how Commercial Screen Readers work also. I have very limited experience of screen readers but it seems that most users find a solution that works for them. Hence the reason I sometimes get requests for a Word version for use with screen readers. In most cases this is simply because the user knows how to use their screen reader with Word, rather than it necessarily being more effective than a PDF. Screen Readers essentially use the document structure and tagging to read out or display the content in an alternative way. They will include the ability to use tab keys and quick keys to navigate the document something that Acrobat does as well. There are many Screen Reader Software packages, some of which are Open Source, a popular commercial package being JAWS. Macs come with a built-in screen reader called VoiceOver.
So the answer is basically yes, but it’s still not that straight forward. Thankfully the increasing migration to mobile devices as our main source of web viewing is indirectly driving accessibility of documents up. While accessibility for a small percent of users with impairments has never been a huge driving force, the need to deliver flexible content for delivery across the widest number of platforms for the mass market is. As a result the software used to generate content must now help deliver final output which is well structured in a simple and efficient way. This is rapidly improving and will continue to do so.