Microsoft PowerPoint (Mac) Accessibility Tutorial
Introduction
PowerPoint, the Microsoft Office slideshow presentation program, has a number of tools the content creator can use to increase the accessibility of produced content. This tutorial will walk Mac PowerPoint users using Powerpoint 2004 or 2008 through the implementation of these features to create an accessible PowerPoint presentation. A tutorial to Windows versions of PowerPoint is also available.
In this tutorial, the accessibility features of Microsoft PowerPoint will be covered through:
- Alternative Text
- Slide Titles
- Descriptive Hyperlinks
- Creating Accessible Templates
- Set Document Language
Alternative Text
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 (shown in the examples below), "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."
As of this writing, the best method for providing alternate text for images using PowerPoint for the Mac is to select the Picture with Caption slide layout and enter alternative text in the caption box.
If you don't want your caption to be visibly seen, you can make the text the same color as your slide. It then appears invisible. Under the Outline tab to the left you can see the text that will be read by a screen reader.
In the 2011 version of PowerPoint for the Mac, Alt text can be added to images by right-clicking them and then selecting format picture. Once in the Format Picture dialog box, click on the Alt text tab and input your desired text alternative into the box. You will want to save your file with a .docx file extension (you change the file extension by selecting the Format drop-down in the Save As dialog box) rather than a .doc to preserve this, as earlier versions on PowerPoint for the Mac do not have the option for this.
Slide Titles
Slide titles are necessary to allow easy navigation of the slideshow by users with screen readers.
For an invisible title, have the titled selected, than enable the Selection Panel from the Arrange drop down panel in the Home tab.
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.
Descriptive Hyperlink Text
Using descriptive text for any hyperlinks used in the presentation will ensure that a link's purpose is understood. Screen readers will read out a URL, but since URLs are not always easy to understood, descriptive text increases clarity for the user.
Place your cursor where you want the hyperlink to appear, right click and select Hyperlink. Mac users can either right-click (control+click) to bring up the same menu or Insert, Hyperlink.
Add descriptive text in the Text to Display field (this is the text users will see) and add the URL in the Address field.
Select OK. This is the resulting hyperlink based on our descriptive text. It takes the user to MSU's home page.
Creating Accessible Templates
In Microsoft PowerPoint, it is possible to create new templates. In doing so, we can make a template with all accessibility functions set in without having to set them every time a new presentation is started.
To start:
- Create a new PowerPoint presentation
- Set all accessibility functions
- File > Save As
- Name accordingly in the Save As box
- In the Format box, select PowerPoint 97-2004 (.pot)
- Select Save
To access the accessible template:
- File > Project Gallery
- Category > My Templates
- Select your template
- Select Open
Set Document Language
Your presentation must be accurately read by assistive technologies, and the best way to do this is to set the language of the presentation. Note: if a different language than the set one is used somewhere else in the presentation, this should be also be indicated.
- Tools > Language
- Select the language you wish to set in the Mark selected text as box
- Select Default…
- Select OK
To apply a language to selected text:
- Highlight the specified text
- Tools > Language
- Select the language you wish to set in the Mark selected text as box
- Select OK