An individual slide should include a description if it is an important step in the process or if it presents a significant concept visually. Some movies, particularly those of recorded demonstrations, may not need descriptions for each individual slide because often several slides cover one concept. In these cases, place the description on the last slide of that group.
When providing a description for an individual slide, it is important to pause the movie on that slide. This provides the user the opportunity to return to the top of the movie and read the description. Otherwise, the movie plays and moves past the slide containing the description.
To make it easier for a screen reader user to understand when a movie is paused, it is recommended that an audio cue, such as a tone, be associated with the Continue button.
To add a description to a slide, use the following steps: