RESNA 26th International Annual Confence
The Power Point HTML Accessibility Plug-in allows Microsoft Power Point presentations to be published in an accessible HTML format for WWW. The tool automatically generates text equivalents for common PPT objects and supports the instructor in generating text alternatives for images that are used in educational settings like pie, bar and scatter point charts. The HTML markup generated exceeds current Section 508 requirements and meets W3C Web Content Accessibility Requirements Double-A conformance.
Microsoft Power Point (PPT) is popular program for creating and showing instructional materials in higher education. Many instructors use PPT for creating and presenting their lecture materials for courses that they are teaching. With the wider use of the WWW to manage and make available course materials, many instructors are publishing their PPT presentations to the WWW using the Web publishing commands built into PPT. The default PPT conversion feature converts the native PPT format to an XML format that can only be viewed with the Internet Explorer Browser. The instructor can reconfigure PPT to generate HTML that can be rendered by other browsers like Netscape Navigator and Opera, but with less flexibility in rendering than the XML version. The simplicity of converting PPT materials to web documents using the built-in feature makes PPT a primary web authoring tool for instructors. Instructors with either little or extensive knowledge of HTML find the convenience of the PPT publishing feature greatly reduces the time needed to prepare instructional materials for the WWW. Since many instructors may not understand web accessibility or are using the tool to mainly save development time, it is important that PPT publishing features support the generation of accessible web materials. This is especially important for students with disabilities to have access to instructional material at the same time as other students.
The current built-in XML and HTML publish to the web features of PPT do not provide the instructor with the ability to generate accessible web materials. For example the instructor has no way to include long descriptions for images, charts, tables and diagrams. The markup only supports a graphical rendering of the presentation and users have little control over the styling of the resulting materials. The PPT HTML accessibility tool is designed to provide the same ease of publishing features as the current built-in web publishing feature, but automatically guide and automate the generation of text equivalents for slide information with graphical content which is required to create accessible web content. In addition it provides the user options for viewing the material in either a graphical or text view using accessible navigation methods and CSS technologies for styling the presentation. The web is a powerful means to provide multiple views of the same information and allows people choices in how they view the content.
The goal of the tool is to allow instructors to use similar publishing commands as the built-in PPT publishing tool but generate accessible web content based on the Web Content Accessibility Guidelines [1] Double-A requirements which exceed the Section 508 Web Accessibility Requirements[2]. A major part of generating accessible content is supporting the instructor in creating text equivalents for graphical information within a PPT presentation. The tool generates valid HTML web pages that provide parallel graphical and text views of each slide in the PPT presentation. The generation of accessible HTML supports the concept of interoperability of the WWW, since both mainstream and specialized browsers for people with disabilities can render the resulting HTML markup. There are two ways that the accessibility tool supports the generation of accessible HTML. The first is to automatically generate alternative equivalents for certain types of PPT content defined by the instructor when they made the PPT original slide was created. This includes information like charts, tables and diagrams that were created using the PPT chart authoring features. In this case the instructor doesn't need to manually generate text equivalents, because they can be generated automatically from the information the instructor has already provided in creating the slide content. Instructors sometimes use images imported from other programs or scanned in from photographs as part of their PPT presentations and in this case alternative equivalents cannot be automatically generated for the images. The tool then guides the instructor in creating the correct alternative equivalent of the image.
| Table 1: Summary of the Types Alternatives Generated for Different Types of Images |
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In the case the instructor has included an image in a presentation and the PPT accessibility tool does not have access to the original information used to generate the image, the instructor must manually enter the information for the text equivalent. In this case the tool prompts the instructor to ask them if the image is a decorative image, an informative image, a data chart or a data table. See Table 1 for a summary of the types of text equivalents needed for different types of images. If the image is a decorative image the user is only required to enter a short description of the image that will serve as the ALT text for the image. If the image is informative, the instructor is asked to not only provide a short description, but also to provide a longer description of the image. The longer description should describe the information the instructor hoped the image would convey to somebody who could see the image. If the image is a bar or pie chart the instructor is prompted with a dialog box to enter the title of the table, and the label/data pairs of each bar in a bar chart or slice of a pie chart. The accessibility plug-in will then generate a properly formatted data table as the text equivalent. The user doesn't need to know any HTML to generate the text alternative, they only need to know the label/data pairs. In the case of an image of a data table the user is prompted with a dialog to identify the number of data rows and columns in the table, the title of the table, the labels for the header cells of the table and the corresponding data for each data cell in the table. By removing the requirement that the instructor know HTML and accessible design practices the PPT accessible Web Publishing tool greatly simplifies the process of converting a PPT presentation into an accessible WWW version.
Version one of the plug-in is anticipated to be available by January 2003, there is a beta version currently available. The new version will take advantage of the C# programming language and will be built to support XML representations of the slides. The XML representation of the slides will differ from the current Microsoft XML representation created using the Microsoft built-in publish to the web feature of PPT. The PPT HTML accessibility plug-in will use XML to create a structured representation of the content in the slide. The current Microsoft representation is designed to only support only a graphical rendering of the slides. The content representation is rendering neutral allowing the XML to be transformed (using XSLT) to graphical and text mostly representations that use the accessibility features of HTML. These views can be linked and published as parallel representations of the same content. This gives the users a choice on how the slide content will be rendered to them. Providing users with choices on how to view information is one of the most powerful features of the web. The tool also creates accessible content by default, rather than by exception as with other authoring tools. Most authoring tools require the author to be knowledgeable about accessible design practices and requires them to learn how to use the features of the tool to create accessible content. This can be a time consuming and frustrating task since many authoring tools make it difficult or impossible to create accessible web materials even when the author is knowledgeable about accessible design practices.
More information and a downloadable version of the Power Point HTML Accessibility plug-in can be found at the following web site:
Current support for this project comes from the Trace Research and Development Center at the University of Wisconsin at Madison (NIDRR grants H133E980008 and H133E990006), Illinois Board of Higher Education, Great Lakes Disability Technical Assistance Center at University of Illinois Chicago (NIDRR Grant H133D010203) and the Division of Rehabilitation - Education Services at the University of Illinois.