Redundancy Principle: Should You Duplicate Narrated Text on Screen?

When you create e-learning courses, do you generally include on-screen text that’s identical to the audio narration? If so, you’re definitely not alone. In fact, virtually everyone has created a course like that at some point. However, just because it’s a common practice doesn’t necessarily mean it’s a good practice. Let’s take a look at what the research says about using redundant on-screen text.

When to Avoid Redundant On-Screen Text 

As Mayer and Clark explain in their book E-Learning and the Science of Instruction, a number of studies have shown that when explaining concepts using visuals, it’s more effective to use audio on its own than to include the same information in both audio and on-screen text.

Researchers believe that there may be a couple of different reasons for this:

1. Learners can only process one visual at a time. If they’re reading the text, they can’t pay attention to the graphics. 
2. Learners may focus more on comparing the text on the screen to what they’re hearing in the audio than on the actual content.

When learners have too many things to process at the same time, they can experience cognitive overload, which can prevent them from learning the material. For this reason, in most cases it’s best to avoid including redundant on-screen text when using visuals to explain content. 

When to Include Redundant On-Screen Text 

However, this doesn’t mean you should never include the same text on the screen and in the audio. Mayer and Clark go on to say that research shows that redundant on-screen text can improve learning in some situations. For example:

• When there aren’t any visuals.
• When content is presented slowly or when learners can control the pace, giving them enough time to process the visuals and on-screen text.
• When the redundant on-screen text is boiled down to a few keywords that support the visuals.
• When the text includes instructions that may need to be referred to later on.
• When the audio on its own may be difficult for learners to understand, for example, if there are terms they may not be familiar with, if it’s not in their native language, or if they have learning or auditory disabilities. If you’re creating a course for a heterogeneous group of learners, you may choose to provide closed captions that learners can turn on and off as needed.

In these cases, the on-screen text actually reduces the mental load and can improve learning outcomes.

The Bottom Line

Depending on the situation, duplicating narrated text on the screen may either help or hinder the learning process. By following the guidelines outlined in this article, you can be sure to only use it when it makes sense. 

To see for yourself how the use of redundant on-screen text can impact the learning experience, check out this example where we’ve presented the same content in a few different ways. Let us know which one you prefer in the comments section below!

More Resources

If you’d like to dig deeper into this and other evidence-based best practices for e-learning design, be sure to check out the book that inspired this article: E-Learning and the Science of Instruction by Ruth Clark and Richard Mayer.

Short on time? Check out these articles where we’ve summarized a few of the other key points presented in their book:

• Personalization Principle: Speaking to Instead of at Your Learners
• Multimedia Principle: Adding Graphics to Words Improves Learning
• Contiguity Principle: Keep Graphics & Related Text Together
• Coherence Principle: Less Material for Better Learning

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