How to add alt text?

  1. Right-click a picture and find View Alt Text.
  2. Write and edit the alt text.
  3. Make your alt text descriptive.
  4. Avoid unnecessary long alt text.
  5. Include tactile graphics when possible.

1. Right-click a picture and find View Alt Text.

the "View Alt Text" option highlighted context menu after right clicking a picture

2. Write and edit the alt text.

The Alt Text pane will show up on the right. You can simply add a description.

This is a screenshot of a PowerPoint slide and the Alt Text Panel. On the left, there is a PowerPoint slide with two pictures which both have some text descriptions below. on the right we see the "Alt Text" pane, which includes the alt text of one picture in one textarea. There is also description of alt text above the textarea. Below the textarea, is a button called "Mark as decorative" above a button "Generate alt text for me".

3. Make your alt text descriptive.

It is important to make your alt text descriptive and specific. For example, the alt text above “This is a profile picture of classic 1980s man who is into rock music with long hair” detailed the picture pretty well. In contrast, you shouldn’t simply say “Customer X”.

For more details on how to write image descriptions, please see this guide.

4. Avoid unnecessary long alt text.

Your alt text shouldn’t be unnecessarily long. Consider why you included that image. What point were you trying to get across? Use this purpose to help you select what details to include. Look at the example below. For the scatter plot and red line, we actually don’t care about the number of points or the color of these points or lines. We want to convey that the line is the singular vector that captures the most variance of these points, meaning that the line is aligned with the points in 2D space.

This is a screenshot of a PowerPoint slide and the Alt Text Panel. On the left, there is a PowerPoint slide with a scatterplot and a red line fitting a regression of the scatter plot. On the right, the alt text is "This graph is the same 2-D scatter plot and a regression line y=x. All the scatter points are surrounded by this line. Even though this is a s-d on a plot, the actual dimension can be captured by a line (the y=x regression line), which is 1-d.".

5. Include tactile graphics when possible.

Complement graphs with tactile graphics when possible. For the dimensionality reduction example, it may be beneficial to add tactile graphics so that the students can “feel” what you are talking about. Please refer to THIS SECTION.