2001 Conference Proceedings

Go to previous article 
Go to next article 
Return to 2001 Table of Contents


Publishing Accessible WWW Presentations from Power Point Slide Presentations

Jon Gunderson, ph.D. and Shi Chao Zhang
University of Illinois at Urbana/Champaign
College of Applied Life Students
Rehabilitation Education Center
1207 S.Oak Street
Champaign, IL 61820

Abstract

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 author in generating text alternatives for images that are commonly used in educational settings like data charts and tables.

Introduction

Microsoft power point (ppT) is popular program for creating and showing instructional materials in higher education. Many instructors use ppT for creating their entire set of 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 built-in ppT features for convert the native ppT format to an HTML or XML format for the WWW. The type of markup generated (HTML or XML) is based on the configuration options of ppT set by the user. The simplicity of converting ppT materials to web documents using the built-in feature makes ppT an important web authoring tool for instructors. Authors with little or extensive knowledge of HTML find the convenience of the ppT publishing feature to greatly reduce the time needed to prepare instructional materials for the WWW. Since many authors may not understand web accessibility or are using the tool to mainly save develop time, it is important that ppT publishing features support the generation of accessible web materials. This is especially important in educational settings for students with disabilities to have access to instructional material at the same time as other students.

The default settings in ppT 2000 generates XML based web documents that currently can only be read with Internet Explorer 4.0 or greater browser. There are other options within the built-in ppT web publishing features to publish in just HTML, but his requires the author to understand the difference between XML and HTML, and even if the author selects HTML settings there is still no built-in capability for the author to provide text equivalents for images, charts, tables and diagrams. The ppT HTML accessibility tool is designed to provide the same publishing features as the built-in web publishing feature, but automatically generate text equivalents for slide information or guide the author in creating text equivalents required to create accessible web content.

Goal of the Tool

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 [WCAG]. A major part of generating accessible content is supporting the author in creating text equivalents for graphical information within the ppT presentation. The tool generates valid HTML web pages that support both the graphical rendering and a text rendering of the information in the ppT presentation. The publication of accessible HTML based web resources supports the concept of interoperability of the WWW, since both mainstream and specialized browsers for people with disabilities support the rendering of HTML based resources. 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 author in making the original slide presentation. This includes information like ppT created charts, tables and diagrams that were defined using the ppT authoring features. In this case the author doesn't need to manually generate text equivalents, because they can be generated automatically from the information the author has already provided in developing the ppT slide. Many times authors use images imported from other programs or scanned in from photographs to include in their ppT presentations. In this case there is no additional information that the author has provided for the accessibility tool to use to generate alternative text equivalents. The accessibility tool detects the images and then prompts the author with choices on what the image represents. There are currently four choices: decorative image, informative image, chart or table. Based on the authors selection the tool guides the author in adding the proper text equivalents.

Table 1: Summary of the Types Alternatives Generated for Different Types of Images
Type of Image Alternatives
Decorative Image Short description of image
Informative Image Short and long description of image
Chart Chart title and label/value pairs for the data in the chart
Table Table title, row and column labels, and table data

Generating Accessible Text Equivalents Automatically for Slides

The HTML accessibility plug-in generates content based on the W3C Web Content Accessibility Guidelines [WCAG]. These guidelines are designed to help authors create accessible web content. The ppT built-in web publishing features currently do not generate content compatible with WCAG. The ppT accessibility plug-in will automatically generate HTML that conforms to WCAG triple A compliance and will automatically generate text equivalents for ppT defined organizational charts, bar charts and data tables. The tool does this by accessing the object model of ppT, which provides access to the data the user entered to create the objects.

Supporting the Author in Manually Creating Text Equivalents for Slides

Many times an author includes an image of a picture or an image of a chart or table generated by another software program. In this case the power point accessibility tool does not have access to the original information used to generate the image and cannot automatically generate alternative equivalents. In this case the tool prompts the user to ask them if the image is a decorative image, an informative image, a data chart or a data table. 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 HTML ALT text for the image. If the image is informative, the author 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 author hoped the image would convey to somebody who could see the image. If the image is a bar or pie chart the author 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 a 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 author know HTML this tool greatly simplifies the process of converting a ppT presentation into an accessible WWW version.

The following images illustrate some of the features available to authors to help them create text equivalents.

Screen shot of selecting the type of image description required

Screen Shot 1: Selecting the type of image description required

Screen shot of selecting the type of chart

Screen Shot 2: Selecting the type of chart

Screen Shot of dialog for entering label/value pairs for a chart

Screen Shot 3: Entering label/value pairs for a bar chart

Current Status of the Tool

The tool is currently being beta tested on the UIUC campus and will be released for public use by November of 2000. More information and a downloadable version of the power point HTML Accessibility plug-in can be found at the following web site:

http://www.rehab.uiuc.edu/ppt

Acknowledgments

I would like to thank project Scale on the UIUC campus and the DRES Merrium Endowment for support students with disabilities on the UIUC campus for their support of this project.

References

[WCAG] Web Content Accessibility Guidelines 1.0 
http://www.w3.org/TR/WCAG10/


Go to previous article 
Go to next article 
Return to 2001 Table of Contents 
Return to Table of proceedings


Reprinted with author(s) permission. Author(s) retain copyright.