PowerPoint & Friends: Accessible Slides on the Web
Terry Thompson
DO-IT, University of Washington
tft@u.washington.edu
For All PowerPoint Solutions
- Use PowerPoint template to ensure good structure
- Avoid inserting text boxes
- Add ALT text for all images, including diagrams
- Select the object
- Right click (or select "Format" from menu)
- Select "Format X" where X is the type of object (e.g., "Format Picture")
- Enter Alt text in "Web" tab
- Add speaker notes to each slide if you plan to export to a video with narration and captions
Technique #1
Make the original PowerPoint available for download
Sample PowerPoint file
- If viewed using Microsoft PowerPoint, a simple slideshow is accessible
- Not all users have PowerPoint
- Fonts are not displayed reliably across computers/operating systems
- The free Microsoft PowerPoint Viewer add-in only works in Windows, and does not work in all browsers
- Some third-party applications (e.g., Open Office) can read PowerPoint files in non-Windows operating systems
- If viewed using the PowerPoint Viewer browser plug-in, the file is NOT necessarily accessible to screen reader users
- Speaker notes feature can be used for attaching notes to slides
Technique #2
Use PowerPoint "Save As Web Page"
Sample MHT file
The File Format
- Creates a single MIME HTML (.MHT) file (as of PowerPoint 2003)
- Easy to distribute, since all graphics and supporting content are compressed within one file
- File format not natively supported by many browsers other than Internet Explorer
- Viewing file in Firefox 2.0 and lower requires the Mozilla Archive Format extension.
The Interface
- Interface includes four frames (navigating the frames with a screen reader is somewhat cumbersome)
- ALT text is present, but is not communicated in a way that screen readers understand (the image is rendered using a VML shape element, rather than an HTML img element
- Unintuitive HTML structure (e.g., no headings or lists)
- Visual layout not rendered reliably in browsers other than Internet Explorer
Technique #3
Use PowerPoint "Save as... Web Page"
Sample HTM file
- File type is HTML - supported by all browsers
- Outputs multiple files, rather than one
- Same interface (and same issues) as Technique #2
- Even though file is .HTM, it contains proprietary markup and is not rendered reliably in browsers other than Internet Explorer
Technique #5
Sample Impatica Presentation
- "Used by over 2000 schools, colleges, and universities"
- Impatica Player is a Java applet
- Slides can be advanced with space bar, but otherwise there is little or no keyboard support
- To use keyboard at all, Java player must first have focus, which requires a mouse click
- Player doesn't commute at all with screen readers
Technique #6
Produce a narrated video
Sample Flash video
Sample Quicktime video
- Many tools support this, including Camtasia, Accordent PresenterOne, and others
- A good multi-modal learning tool: Slides aren't the sole source of information
- Must be captioned in order to provide access to people who can't hear the audio
- Lecturer must verbalize content of the slides, just as they would in a live presentation
A Footnote About Captions
- Captions in this demo were created using Camtasia Studio version 4
- Very easy to create captions (requires eyesight and use of mouse)
- Output for all video formats (other than Flash) is open captions
- In Flash output, closed captions are presented as an overlay atop screen content. This can be hacked post-production to be displayed more optimally, but the process is not well documented by TechSmith (maker of Camtasia).
Technique #7
Convert PowerPoint to HTML
The current web page page provides an example of this method
- Copy outline
- Paste it as text into web authoring software
- Select slide titles: Convert them to <h1> or <h2>
- Convert bulleted lists to <ol>
- Only takes a few minutes for a simple PowerPoint presentation
- Output is one fully accessible file
- Images, tables, and other relatively complex content would require significantly more re-writing of content in HTML version
Technique #8
Convert PowerPoint to Adobe PDF
Sample PDF
(requires Adobe Acrobat Reader)
- By default, creates a reasonably accessible "tagged PDF"
- Depending on slide content, the tagged PDF structure may require editing in Adobe Acrobat for full accessibility
- Fonts/presentation are preserved across computers
- A single file, easy to upload and circulate
- Not all assistive technologies support PDF Accessibility
Technique #9
Sample Illinois Wizard Output
- Wizard prompts for short and long descriptions of visual elements
- Produces multiple versions to meet a variety of users' needs
- "Text only" is the most fully accessible version for screen reader users
- "Text mostly" version has a few anomalies
- "Graphic" version does not include short or long descriptions
Technique #10
Convert PowerPoint to XHTML using LecShare
Sample LecShare Output
- Prompts for short and long descriptions for visual elements, plus other accessibility issues.
- Exports to valid accessible HTML/CSS
- All content is provided in one version
- Audio can be recorded for the entire presentation or for each slide individually (exports to Quicktime)
- Speaker notes are used as closed captions
Technique #11
Sample HTML Slidy Presentation
- All content is in one valid XHTML file
- Markup file according to instructions
- Uses CSS and Javascript to display as slideshow
- Without Javascript, displays as web page
- Output is standards-compliant,cross-platform, cross-browser, and easy to distribute, but...
- Assigned hotkeys conflict with screen reader hotkeys. Screen readers don't work well, if at all, unless the user disables Javascript.
Technique #12
Sample S5 Presentation
- S5 stands for "Simple Standards-Based Slide Show System"
- Same approach as with W3C slide tools
- Seems to work somewhat better with screen readers than W3C slide tools, but there are still key conflicts.