By: Lori Bailey, OSU Web Accessibility Center, January 2005

Before wading through what can be a complex and time-consuming process of preparing a document for conversion and checking the resulting PDF for accessibility, designers need to assess the advantages and disadvantages of choosing PDF as a portable, non-proprietary, alternate format for users, in particular for users of assistive technology. This article explores some situations where PDF might be the better choice and those situations where a more accessible format is required.

Benefits of PDF in the Classroom

• Distribution of free Adobe Reader means a vast majority of students will have easy access to a "viewer" that can display and manipulate (at least slightly copy/paste/print) the document to meet students' needs.

• Can be done quickly, with PDF toolbar in Word or through the "Print to PDF" option. Little training is required to create a basic PDF document from any Word document.

• PDFs can be "locked" against editing by students.

• Known population of users. Those who require more accommodation than the standard PDF can be identified early in the quarter and addressed on a "on-demand" basis.

Limitations of PDF in the Classroom

• PDFs are much larger files (2-3 times as large) than MS Word files: requires more space to store and more resources to distribute (e.g. more server space, larger files allowed through e-mail, longer download times via the web).

• In some cases, students need to have the latest version of Adobe Reader installed to use all the features of the document (especially forms). MAC, Linux, and users with other platforms may not have access to Adobe Reader or may use another PDF viewer that does not have the same support for your document.

• PDFs can be confusing, particularly when viewed within an Internet browser window different toolbars to save and print and limited/clunky navigation through the document.

PDF Beyond the Classroom

As long as the intended use of your documents is for your students in your classroom, you can choose to offer fewer accessibility features and ask students who need additional accommodations to make those requests as needed (provided you are prepared to respond to those requests in a timely manner). Once you move to distributing your document to a wider, unknown, population (such as on a web site open to the public), you must offer a fully accessible version by default. That is, you cannot post inaccessible versions and wait for a user to make an accommodation request. You must provide at least one version of the document that meets all of the OSU Minimum Web Accessibility Standards (rev. June 2004).

PDF and HTML The Ideal Combination

Of course, just because you are required to offer an accessible version, does not mean you must offer an accessible PDF version. In fact, as many designers have discovered, creating accessible PDF can be a difficult and complicated task. Even more revealing, some accessibility experts argue that, given the current level of technical capabilities of both Adobe and assistive technology software, there is no such thing as a fully accessible PDF. Even the most well-designed and well-prepared PDF document will have fundamental limitations for assistive technology users that are not true of other document formats, such as HTML.

Because of these limitations, the WAC recommends that when distributing documents to an unknown population, designers offer both PDF (for convenience and printing) and HTML (for accessibility) formats.

Why HTML Over PDF?

The PDF format was originally designed to maintain specific formatting information of a document, so that it could be printed and reprinted in its original form. HTML was originally designed to display text regardless of, even despite, formatting across platforms and on different technology. PDF was designed to printed. HTML was designed to be displayed. PDF is static. HTML is fluid.

This inherent flexibility in HTML offers the perfect platform for developing accessibility features. Unlike PDF, HTML can be easily customized by users to change colors, change fonts and font sizes, display on different size screens, and using a variety of software. HTML also includes a number of tools to aid navigation of documents, such as links, anchors, and structural elements (headings, paragraphs, tables); all of which have special support when rendered via assistive technology. PDFs, in comparison, can be navigated by page or by user-defined bookmarks, but not usually by paragraph, header, or table. While HTML documents can, nonetheless, be created using poor design and incorrect tagging, resulting in a fairly inaccessible document, most simple HTML documents will automatically include far more accessibility features than a PDF document created explicitly with accessibility in mind.

Conclusions

PDF can offer a quick and easy method to distribute classroom documents to students and be assured they will have the tools to open and use them. However, for general Web distribution, documents must either be created using all available accessibility features in Adobe Acrobat or, in most cases the preferred method, must be accompanied by an accessible format (HTML).