Do educational animations need a sound track?

Incorporating an audio track with the animation is often better than just writing a textual explanation. Here are five principles to consider in deciding when and how to incorporate a voiceover to your animation.

• modality principle
• temporal contiguity principle
• voice principle
• personalisation principle
• redundancy principle

There are five multimedia principles relating directly to the use of narrations with animations. The modality principle has received the strongest support from the research and simply states that animation and narration is better for student learning than animation and on-screen text. Consider the following animation. Do you think it would be as effective if the narration was in the form of text?

One explanation of why narration and animation might be more effective than text and animation considers how well the instructional design aligns with ideas about human cognitive architecture. In the cartoon below, we see that when text and animation are presented together (left) that the visual attention must be shared between the two disparate sources of information and that they must then be integrated in working memory. If however narration and animation are presented together, as recommended by the modality principle (right), so that the words and pictures correspond (temporal contiguity principle), then the user can make more efficient use of the dual-channel working memory i.e. phonological loop and visuo-spatial sketchpad. As a result less time needs to be spent integrating the information in working memory.

The synchronisation of the audio narration with the animations is referred to as the temporal contiguity principle. Together with the voice principle (a human voice is better than a robotic voice) it guides the designer as to how one can optimise the benefits of using an audio narration.

The personalisation principle (i.e. a casual presentation, perhaps using the 2nd person, is better than an official sounding presentation) helps set up social norms that usually require the user to listen attentively and thus effective student learning is more likely to ensue.

Finally, in terms of principles relating to the use of an audio narration, the redundancy principle states that audio plus the textual version of the audio is not as effective as presenting only the audio narration. Often in powerpoint presentations, the presenter will read the text out from the slide. Do you find such presentations to be useful learning experiences?

Nevertheless, the example below shows how we decided to set aside this principle, in response to user feedback that suggested speakers of English as a second language benefitted from a text version of the audio track. So we don't follow these principles as laws: we violate them if we believe that they are over-ridden by other considerations.

The above five principles relate to the use of narration rather than textual explanation. Hegarty (2005) points out that language assists deeper understanding of animations and forms an essential component of the broader environment in which complex animations are embedded. We have used a range of combinations our our multimedia teaching, such as Physclips and Einsteinlight. In these , we use an audio track to explain what is being viewed in the animation and for explaining why it is so. We then use much more detailed text (available via links) to answer expected questions, to consider more cases and to expand on issues raised.