In Clark and Mayer’s eLearning and the Science of Instruction, they say that the research generally supports using narration with on-screen visuals. Adult learners retain more from a narration plus visuals approach than from reading on-screen text. They call this the “modality principle.”
Generally speaking, when you have narration, you shouldn’t also have that same text on the screen. This is called the “redundancy principle.” Clark and Mayer note some exceptions when text should be shown on screen (pp. 87-88, 107-108 in the 1st ed):
- Complex Text: Complex text like mathematical formulas may need to be both on-screen and in narration to aid memory. (In practical experience, I also do this for text that has to be memorized word for word, such as screening questions for addiction.)
- Key Words: Key words highlighting steps in a process or technical terms
- Directions: Directions for practice exercises. “Use onscreen text without narration to present information that needs to be referenced over time, such as directions to complete a practice exercise.”
- No Graphics: When there are no graphics or limited graphics on the screen
- Language Difficulties: When the audience has language difficulties. I have used redundant on-screen text for an audience with very low literacy and a high percentage of learners with English as a second language. It might be enough to simply provide a transcript or closed captions in those situations so people who don’t need it can ignore or turn off the text.
In practical terms, I’ve found that if every page has narration and you suddenly have no narration for a practice exercise, some learners think something’s broken on the page. I generally have the narrator say something short to introduce the practice exercise, but leave the directions as on-screen text.
However, it’s also tiring to listen to a voice. I usually don’t provide audio feedback on practice activities to give people a break. I’ll sometimes provide other kinds of interaction or content delivery to provide a break from the audio (tabs or “click to reveal” text).
In the book, Clark and Mayer say this:
“Does the modality principle mean you should never use printed text? Of course not. We do not intend for you to use our recommendations as unbending rules that must be rigidly applied in all situations. Instead, we encourage you to apply our principles in ways that are consistent with the way that the human mind works—that is, consistent with the cognitive theory of multimedia learning rather than the information delivery theory.”
The principle of avoiding redundant on-screen text is sometimes treated as sacrosanct. I’ve seen some big names in the field practically yell that this is a firm rule that should never be broken. In real life, it’s not as clear cut, as even Clark and Mayer acknowledge. There’s plenty of redundant on-screen text that has no business being there. You should be thoughtful and intentional if you’re going to provide on-screen text. Generally, it shouldn’t be there, and you need a real reason to break the redundancy principle.
What are your experiences with audio, especially with on-screen text? What have you found works with your audiences?