Do your e-learning courses include on-screen text with identical audio narration? If so, you’re definitely not alone. In fact, I’ll bet virtually everyone has taken, or 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.
A number of studies have shown that learning is depressed by an average of 79% when a graphic is explained by both on-screen text and a duplicative audio narration. 
Why? Learners can only process one thing visually at a time. If they’re reading the text, they can’t look at the graphics simultaneously. However, presenting the text as audio narration lets learners process it with their ears, and frees their eyes to focus on the graphic being explained.
Some designers might be tempted to include the redundant on-screen text as a way to accommodate both auditory and visual learning styles. There isn’t any evidence to show it helps boost learning, so it's not likely to be a good investment of your time and resources.
Does this mean you should never use on-screen text? Not at all. The redundancy principle is only relevant when the text explains a graphic. When there's no other visual content on the screen, research suggests that learning improves when you present the words as text and narration.
Here are a few other factors that may sway you toward displaying the text on-screen:
- Cost: If you can’t record your own narration and you can’t afford to outsource it.
- Technical constraints: If your audience includes learners who are viewing your course on devices without audio capability.
- Non-native language: If your audience includes learners who would have trouble processing the spoken words.
- Instructions: If you have any practice elements or exercises that might require your learners to refer back to the instructions.
Check out Tom’s demo demonstrating a variety of designs for the same content to see which one you think is the most effective.
Narration with redundant text
Visual Design and narration without redundant text
While there is rarely a foolproof recipe for designing e-learning and other multimedia projects, you’ll definitely make better decisions if you know the basic design principles for how people learn. If you’re looking for a great place to start, check out, “E-learning and the Science of Instruction” by Ruth Clark and Richard Mayer.
1. Clark, R. C., and R. E. Mayer. E-Learning and the Science of Instruction, 2nd edition (San Francisco: Pfeiffer, 2007).
2. Mayer, R. E., “Introduction to Multimedia Learning,” in R. E. Mayer, ed. The Cambridge Handbook of Multimedia Learning(New York: Cambridge University Press, 2005).
Follow us on Twitter and come back to E-learning Heroes regularly for more helpful advice on everything related to e-learning. If you have any comments, please share them below.