Integrating the multimedia assets of a course can raise a host of issues. In my world, this can be as simple as explaining to a client why screens of text with an out-of-sync voice over will not be effective—to more complex issues, such as determining whether an animation will promote greater comprehension than a series of stills.
Although we know it can be advantageous to present content through multiple forms of media, the big question is how to integrate the mediums.
When deciding on these issues, I use two principles from cognitive science as guidelines that I think you’ll find helpful too. One is known as the Split-attention Effect and the other is the Redundancy Principle. Both principles are important.
The split-attention effect occurs when a person is required to process two or more varied sources of information simultaneously, either of which can’t be understood in isolation. A typical way this occurs in online learning is when an explanation is displayed on one part of the screen, while a visual, such as a diagram or animation, is presented on another part of the screen.
See the example showing the effects of secondhand smoke, produced by the Centers for Disease Control, on the right. Although the animation is well-done, the viewer must hold the textual explanation in working memory, while engaging with the visual.
This type of cognitively demanding task will result in losing some of the information needed to understand both sources of content, causing difficulties in processing the material. To compensate, most people will shift their attention back and forth, which many find frustrating.
Integrate Text with Animation—Carefully
The main fix for avoiding the split-attention effect is to integrate the media so that learners don’t need to process disparate sources of information simultaneously. For example, in the sample referred to above, the textual explanation could be entirely removed from the visual and replaced as short phrases directly in the animation, as shown in the mock-up here.
Be careful that the viewer doesn’t miss the animation while reading the on-screen text. As a safeguard, you can briefly slow down or stop the animation while text is displayed. In addition, adding user controls will make an animation a more effective instructional format.
Replace One Modality with Another
Another integration approach that may be more effective is to replace one modality with another. For example, the text-based explanation could be replaced with well-synchronized audio. Research shows this to be quite effective for learning. When using mixed modalities, learners don’t need to make a huge effort to integrate the information. It’s done for them in the media itself.
The Redundancy Principle
There is one word of caution when integrating different mediums—avoid redundant content. Redundancy occurs when the same information is presented in multiple formats. The redundancy effect reduces rather than increases learning because redundancy places unnecessary demands on one’s cognitive resources. For example, when displaying graphics, avoid using text when a narrated voice over is playing. Otherwise, learners will most likely read the text and miss some of the audio. Rather than using text to call attention to a specific part of a graphic, a simple pointer or other visual cue should suffice.
If you find it difficult to remember all of these guidelines, simply put yourself in the place of the learner or viewer. Notice the cognitive effort that’s required to perceive, process and comprehend the content you’re presenting. This will give you a sense of which approaches cause cognitive overload and which approaches are well-integrated and promote learning.
Multimedia Learning by Richard E. Mayer