Design Principle
Include accessible alternatives for content created in non-HTML format (Word, PDF, PowerPoint, etc)
Web pages are increasing being used to distribute all types of electronic documents. These are either available for download to be viewed on the desktop using the native application, or opened within the browser using a plug-in. Be sure to include a link to download the accessible plug-in on your page. Plug-ins for MS Office documents are called Viewers. Viewers let you read and print the document but not edit and save the document. Viewers for MS Office can be downloaded from the Microsoft Office Site.
All electronic documents, including those distributed via the web or available for download in their native formats must be crafted with accessibility in mind.
Common Document Formats Distributed on the Web
Word Processed Documents
While HTML is the preferred format, word processed documents include Rich Text Format (.rft), Text (.txt), MS Word (.doc), MS Works (.wps), WordPerfect (.wpd) and OpenOffice. These can be downloaded and viewed using the native application or Word Viewer 2003. These documents can be quite large and are often converted to PDF format for distribution on the web.
While these documents are generally accessible to screen readers, their readability can be optimized by using styles built into the software for formatting text and container elements like paragraphs, lists, tables etc.
Spreadsheets
Excel documents can be downloaded and viewed on the desktop or using native Excel or Excel Viewer. These documents are generally accessible to screen readers. Avoid publishing Excel Documents as HTML document or as PDF for mat.
PowerPoint Presentation
PowerPoint Slides can be distributed in many formats:
- Native PowerPoint Slides: these require full version of PowerPoint or a PowerPoint Viewer. The viewer comes installed in newer versions of IE. However, while they need to be downloaded and viewed in other browsers, they can be best viewed using IE.
- Published as HTML File: this generates many files and is not very accessible to screen readers. IE renders the page in a confusing frame layout without usable "alt text" for images. Other browsers render each slide as a single graphic, without any "alt text".
- Converted to Tagged PDF File: the PDF files are accessible as long as the original presentation has been created with accessibility in mind
- Convert to Accessible PowerPoint HTML Slides using third party tools: Examples of tools are : Web Accessibility Wizard ; LecShare (University has site license) and PPT2HTML .
PDF Documents
Portable Document Format (PDF) is a file format developed by Adobe to deliver and render on the web, documents created for print. They require a plug-in called Adobe Reader. The current versions of Adobe Reader can be configured by the user for their needs.
PDF file format include documents created by word processors, spreadsheets, presentations tools and other tools. They can be created as an:
- Image: (inaccessible) a graphical representation of the original document created by scanning the original document.
- Searchable Image: (partially accessible) consisting of an image + text version of the original document. They are usually created from word processor and the other document formats and the text is searchable.
- Tagged Document: (truly accessible) a true electronic document, with searchable text and information on content elements, the semantic structure and presentation attributes. These are converted from MS Office and Adobe Products and can be retrofitted using the Acrobat Editor.
