Creating Accessible PowerPoint Presentations
Microsoft PowerPoint has a number of tools to make produced content accessible. This tutorial will walk Windows PowerPoint users through the implementation of these features to create an accessible PowerPoint presentation. A tutorial to Mac versions of PowerPoint is also available.
In this tutorial, the accessibility features of Microsoft PowerPoint will be covered through:
Currently, the Windows Operating System (OS) offers content creators more opportunity to create accessible PowerPoint presentations than the Mac OS.
Alternative text for images, charts, graphs, and tables is vital to ensuring that users with visual impairments have access to information included in these visuals. This descriptive text should be limited to 120 characters for simple images, while the alternative text for graphs, tables, and complex images (such as detailed maps and diagrams) should give a brief summary of the included information. Alternative text should provide sufficient information so that users who are unable to see them are still able to understand what they convey. Images used for purely decorative purposes (i.e., those that do not provide any meaningful information) should not have alternative text. If the body of the document already contains a sufficiently detailed description in close proximity to the image, the alternative text can simply identify the image so that the reader knows when it is being referred to.
While there are no hard and fast rules for determining what alternative text should say (it depends on the image, its context, the intent of the author, etc.), one simple trick is to imagine describing the image to someone over the phone. The more important an image's content is, the more descriptive the alternative text should be.
For the MSU wordmark ,"Michigan State University wordmark" would be appropriate for most documents. A graphic design document describing the introduction and use of different branding marks at MSU might require a more detailed description, if the specific formatting of the text would be important to the reader.
For charts and graphs, chart type (i.e., bar, pie, line, etc.), data type or axes, overall trends or patterns, and relevant data points should be described. For example, a simple chart might have the following alternative text: "Bar chart of number of traffic fatalities in Ingham county from 2008-2010. Fatalities have increased for the last two years. There were 121 fatalities in 2008, 157 in 2009, and 160 in 2010."
Adding Alt Text to Images
PowerPoint 2007 and 2010 (screenshots are from PowerPoint 2007 and PowerPoint 2010 respectively).
Right click on an image and choose Size and Position.
Select the Alt Text tab. Enter your alt text into the Description field.
Close the Format Picture window after you have entered your description.
Adding Alt Text to Charts, Graphs, and Tables
Select the chart or graph and under the Format tab on the ribbon, select the expansion icon next to Size in the bottom right corner of the drop down menu.
This will bring up the Size and Position window. Select the Alt Text tab and enter a brief description of the chart, graph, or table’s information.
Right click on the chart or graph and choose Format Chart Area.
This will open a dialog window. Select the Alt Text tab. Enter alt text in the Description box.
To Add Alternative Text for Tables
The option for adding alternative text to a chart or graph is not turned on by default. The feature must be made available before alternative text is added. To enable alternative text for charts and tables, navigate to the fly-out menu (known as the Quick Access Toolbar) at the top of the ribbon and choose More Commands.
Select Customize on the left (Word 2010 users will see Quick Access Toolbar). Use the drop-down menu, Choose commands from and select Commands Not in the Ribbon.
Select Alt Text and the Add button to add the option to your Quick Access Toolbar.
You will now have easy access to alternative text for charts and graphs from the Quick Access Toolbar.
Highlight the chart or graph wish to add alt text to, and click the alternative text button that you just set up in the Quick Access Toolbar. Select the Alt Text tab and insert an alternative text description. Word 2010 users will type the description in the Description box.
Slide titles are necessary to allow easy navigation of the slideshow by users with screen readers.
For an invisible title, you can enable the Selection Panel from the Arrange drop down panel.
The Selection and Visibility panel will appear on the right. You can then toggle the visibility of a title by clicking the eye icon next to the title.
These invisible titles will be read off by a screen reader and will indicate to the users the purpose of the slide without creating unnecessary visual clutter.
Screen readers will read each slide in a particular order. It is important to manually verify the order in which each slide is arranged to ensure the information makes sense when read aloud.
Go to the Home tab and in the Drawing section, select the Arrange drop down list and choose Section Pane (Selection Pane in 2007 version).
Reading order in the Selection and Visibility panel is done from bottom to top. In the following image, the visual order of the slide does not match the order in which a screen reader would read the slide. The MSU wordmark (Picture 8) would be read second, not first, as reading order is done from bottom to top in the selection pane.
Use the Re-Order buttons at the bottom of the pane to reorder the slide elements as necessary until the order is correct. Now, the wordmark (Picture 8) will be read first.
To ensure colorblind viewers can access and understand your presentation, a few basic guidelines should be adhered to:
- Avoid using the colors red, green, and orange
- Use textures instead of colors in graphs
- Draw attention to important information on slides by circling it rather than changing its color
- Use high contrast colors
To check your slideshow presentation for color contrast, you can render it in grayscale coloring. Select the View tab and then click on Grayscale.
Here you can select the Grayscale option and test your presentation for contrast. If it is difficult to differentiate between items, then your color contrast might not be sufficient. Alternatively, color contrast can be checked using the Colour Contrast Analyser.